From 20e8f905d05f2d8f390d0e2ef10f1a4a1289967c Mon Sep 17 00:00:00 2001
From: Viktor Hofer <viktor.hofer@microsoft.com>
Date: Sat, 12 Feb 2022 13:07:16 +0100
Subject: [PATCH] Don't use Targets* helper properties in libs (#64500)

* Don't use Targets* helper properties in libs projs

This change makes it possible to migrate 200+ (ref+src) projects to use
TargetFramework instead of TargetFrameworks which avoids the additional
outer build evaluation and invocation which ultimately makes the overall
build faster.

Targets* properties (i.e. TargetsWindows, TargetsAnyOS, TargetsUnix,
etc.) rely on the TargetFramework property which usually are set
inside a project. The TargetFramework property is only
available before a project specifies it if it's explicitly set in a props
file or if the project is cross-targeting and the outer-build dispatches
into the inner-build. During the dispatch, the TargetFramework property
is passed in as a global property.

Until now that behavior wasn't a problem because every libraries project
cross-targeted (by setting the TargetFrameworks property) even though
many only include a single TargetFramework (i.e. NetCoreAppCurrent).

To allow projects to use the TargetFramework property instead of
TargetFrameworks, the Targets* helper properties can't be calculated
anymore early in a props file as the TargetFramework property isn't set
at that time.

In general, the guidance by the SDK/msbuild team is to not read from the
TargetFramework property before the project sets it
(in a property group). That effectively means that the TargetFramework
property shouldn't be used in props files at all.

Therefore these helper properties can't be used anymore for property
conditions and I'm replacing their usage with TargetPlatformIdentifier
comparisons for both properties and items.
In nearly all cases, the Targets* helper properties can be replaced with
TargetPlatformIdentifier checks on items and in the few cases where
TargetsUnix or TargetsLinux marks multiple tfms as compatible, the exact
tfms must be used instead for the TargetPlatformIdentifier comparison.

Whenever a project needs to condition properties on the platform, I'm
first setting the TargetPlatformIdentifier the same way the SDK sets it
so that the SDK later doesn't need to set it again to avoid the
additional expensive msbuild function call.

* Use TargetFramework singular to avoid outer builds

Use TargetFramework instead of TargetFrameworks property whenever a
projects only targets a single target framework. This avoid unnecessary
outer builds and evaluations and makes the build faster.
---
 Directory.Build.props                         |   1 +
 docs/coding-guidelines/project-guidelines.md  |  76 ++++++++-----
 eng/BeforeTargetFrameworkInference.targets    |  19 +++-
 eng/TraversalSdk.AfterTargets.targets         |  18 ++++
 eng/Version.Details.xml                       |   4 +-
 eng/Versions.props                            |   2 +-
 eng/packaging.targets                         |   6 +-
 eng/targetframeworksuffix.props               | 101 ------------------
 eng/testing/tests.props                       |   4 +-
 eng/versioning.targets                        |  26 +++--
 .../Common/tests/Common.Tests.csproj          |   8 +-
 src/libraries/Directory.Build.props           |   1 -
 .../ref/Microsoft.CSharp.csproj               |   2 +-
 .../src/Microsoft.CSharp.csproj               |  10 +-
 ...icrosoft.Extensions.Hosting.Systemd.csproj |   4 +-
 ...soft.Extensions.Logging.Generators.targets |   2 +-
 .../ref/Microsoft.VisualBasic.Core.csproj     |   2 +-
 .../src/Microsoft.VisualBasic.Core.vbproj     |  10 +-
 .../ref/Microsoft.Win32.Primitives.csproj     |   2 +-
 .../src/Microsoft.Win32.Primitives.csproj     |   2 +-
 ...rosoft.Win32.Registry.AccessControl.csproj |   6 +-
 .../ref/Microsoft.Win32.Registry.csproj       |   2 +-
 .../src/Microsoft.Win32.Registry.csproj       |   8 +-
 .../src/Microsoft.Win32.SystemEvents.csproj   |   5 +-
 .../Microsoft.XmlSerializer.Generator.csproj  |   2 +-
 .../ref/System.AppContext.csproj              |   2 +-
 .../src/System.AppContext.csproj              |   2 +-
 .../System.Buffers/ref/System.Buffers.csproj  |   2 +-
 .../System.Buffers/src/System.Buffers.csproj  |   2 +-
 .../ref/System.Collections.Concurrent.csproj  |   2 +-
 .../src/System.Collections.Concurrent.csproj  |   2 +-
 .../ref/System.Collections.NonGeneric.csproj  |   2 +-
 .../src/System.Collections.NonGeneric.csproj  |   2 +-
 .../ref/System.Collections.Specialized.csproj |   2 +-
 .../src/System.Collections.Specialized.csproj |   2 +-
 .../ref/System.Collections.csproj             |   2 +-
 .../src/System.Collections.csproj             |   2 +-
 .../System.ComponentModel.Annotations.csproj  |   2 +-
 .../System.ComponentModel.Annotations.csproj  |   2 +-
 .../System.ComponentModel.Composition.csproj  |   4 +-
 ...stem.ComponentModel.EventBasedAsync.csproj |   2 +-
 ...stem.ComponentModel.EventBasedAsync.csproj |   2 +-
 .../System.ComponentModel.Primitives.csproj   |   2 +-
 .../System.ComponentModel.Primitives.csproj   |   2 +-
 ...System.ComponentModel.TypeConverter.csproj |   2 +-
 ...System.ComponentModel.TypeConverter.csproj |   2 +-
 .../ref/System.ComponentModel.csproj          |   2 +-
 .../src/System.ComponentModel.csproj          |   2 +-
 .../System.Console/ref/System.Console.csproj  |   2 +-
 .../System.Console/src/System.Console.csproj  |  12 +--
 .../tests/System.Console.Tests.csproj         |   4 +-
 .../ref/System.Data.Common.csproj             |   2 +-
 .../src/System.Data.Common.csproj             |   2 +-
 .../ref/System.Data.DataSetExtensions.csproj  |   2 +-
 .../src/System.Data.DataSetExtensions.csproj  |   2 +-
 .../src/System.Data.Odbc.csproj               |  11 +-
 .../tests/System.Data.Odbc.Tests.csproj       |  15 +--
 .../src/System.Data.OleDb.csproj              |  11 +-
 .../ref/System.Diagnostics.Contracts.csproj   |   2 +-
 .../src/System.Diagnostics.Contracts.csproj   |   2 +-
 .../ref/System.Diagnostics.Debug.csproj       |   2 +-
 .../src/System.Diagnostics.Debug.csproj       |   2 +-
 ....Diagnostics.DiagnosticSource.Tests.csproj |   2 +-
 ...ystem.Diagnostics.EventLog.Messages.csproj |   2 +-
 .../src/System.Diagnostics.EventLog.csproj    |   7 +-
 .../System.Diagnostics.FileVersionInfo.csproj |   2 +-
 .../System.Diagnostics.FileVersionInfo.csproj |  11 +-
 ...m.Diagnostics.FileVersionInfo.Tests.csproj |   4 +-
 ...stem.Diagnostics.PerformanceCounter.csproj |   7 +-
 .../ref/System.Diagnostics.Process.csproj     |   2 +-
 .../src/System.Diagnostics.Process.csproj     |  39 ++++---
 .../System.Diagnostics.Process.Tests.csproj   |  10 +-
 .../ref/System.Diagnostics.StackTrace.csproj  |   2 +-
 .../src/System.Diagnostics.StackTrace.csproj  |   2 +-
 ...Diagnostics.TextWriterTraceListener.csproj |   2 +-
 ...Diagnostics.TextWriterTraceListener.csproj |   2 +-
 .../ref/System.Diagnostics.Tools.csproj       |   2 +-
 .../src/System.Diagnostics.Tools.csproj       |   2 +-
 .../ref/System.Diagnostics.TraceSource.csproj |   2 +-
 .../src/System.Diagnostics.TraceSource.csproj |   2 +-
 .../ref/System.Diagnostics.Tracing.csproj     |   2 +-
 .../src/System.Diagnostics.Tracing.csproj     |   2 +-
 .../System.Diagnostics.Tracing.Tests.csproj   |   2 +-
 ...DirectoryServices.AccountManagement.csproj |   7 +-
 .../System.DirectoryServices.Protocols.csproj |  15 +--
 .../src/System.DirectoryServices.csproj       |   7 +-
 .../System.DirectoryServices.Tests.csproj     |   4 +-
 .../src/System.Drawing.Common.csproj          |  22 ++--
 .../ref/System.Drawing.Primitives.csproj      |   2 +-
 .../src/System.Drawing.Primitives.csproj      |   8 +-
 .../ref/System.Dynamic.Runtime.csproj         |   2 +-
 .../src/System.Dynamic.Runtime.csproj         |   2 +-
 .../ref/System.Globalization.Calendars.csproj |   2 +-
 .../src/System.Globalization.Calendars.csproj |   2 +-
 .../System.Globalization.Extensions.csproj    |   2 +-
 .../System.Globalization.Extensions.csproj    |   2 +-
 .../ref/System.Globalization.csproj           |   2 +-
 .../src/System.Globalization.csproj           |   2 +-
 .../ref/System.IO.Compression.Brotli.csproj   |   2 +-
 .../src/System.IO.Compression.Brotli.csproj   |   9 +-
 .../ref/System.IO.Compression.ZipFile.csproj  |   2 +-
 .../src/System.IO.Compression.ZipFile.csproj  |   2 +-
 ...System.IO.Compression.ZipFile.Tests.csproj |   2 +-
 .../ref/System.IO.Compression.csproj          |   2 +-
 .../src/System.IO.Compression.csproj          |   4 +-
 .../System.IO.FileSystem.AccessControl.csproj |   2 +-
 .../System.IO.FileSystem.AccessControl.csproj |  19 ++--
 .../ref/System.IO.FileSystem.DriveInfo.csproj |   2 +-
 .../src/System.IO.FileSystem.DriveInfo.csproj |   4 +-
 ...ystem.IO.FileSystem.DriveInfo.Tests.csproj |   8 +-
 .../System.IO.FileSystem.Primitives.csproj    |   2 +-
 .../System.IO.FileSystem.Primitives.csproj    |   2 +-
 .../ref/System.IO.FileSystem.Watcher.csproj   |   2 +-
 .../src/System.IO.FileSystem.Watcher.csproj   |  23 ++--
 .../System.IO.FileSystem.Watcher.Tests.csproj |   6 +-
 .../ref/System.IO.FileSystem.csproj           |   2 +-
 .../src/System.IO.FileSystem.csproj           |   2 +-
 ...ileSystem.DisabledFileLocking.Tests.csproj |   2 +-
 .../tests/System.IO.FileSystem.Tests.csproj   |   6 +-
 .../ref/System.IO.IsolatedStorage.csproj      |   2 +-
 .../src/System.IO.IsolatedStorage.csproj      |  24 ++---
 .../System.IO.IsolatedStorage.Tests.csproj    |   4 +-
 .../ref/System.IO.MemoryMappedFiles.csproj    |   2 +-
 .../src/System.IO.MemoryMappedFiles.csproj    |   4 +-
 .../System.IO.MemoryMappedFiles.Tests.csproj  |   4 +-
 .../ref/System.IO.Pipes.AccessControl.csproj  |   2 +-
 .../src/System.IO.Pipes.AccessControl.csproj  |   7 +-
 .../ref/System.IO.Pipes.csproj                |   2 +-
 .../src/System.IO.Pipes.csproj                |  16 +--
 .../tests/System.IO.Pipes.Tests.csproj        |   6 +-
 .../src/System.IO.Ports.csproj                |  20 ++--
 .../tests/System.IO.Ports.Tests.csproj        |   2 +-
 .../System.IO.UnmanagedMemoryStream.csproj    |   2 +-
 .../System.IO.UnmanagedMemoryStream.csproj    |   2 +-
 src/libraries/System.IO/ref/System.IO.csproj  |   2 +-
 src/libraries/System.IO/src/System.IO.csproj  |   2 +-
 .../ref/System.Linq.Expressions.csproj        |   2 +-
 .../src/System.Linq.Expressions.csproj        |  11 +-
 .../ref/System.Linq.Parallel.csproj           |   2 +-
 .../src/System.Linq.Parallel.csproj           |   2 +-
 .../ref/System.Linq.Queryable.csproj          |   2 +-
 .../src/System.Linq.Queryable.csproj          |   2 +-
 .../System.Linq/ref/System.Linq.csproj        |   2 +-
 .../System.Linq/src/System.Linq.csproj        |   6 +-
 .../src/System.Management.csproj              |   5 +-
 .../System.Memory/ref/System.Memory.csproj    |   2 +-
 .../System.Memory/src/System.Memory.csproj    |   2 +-
 .../src/System.Net.Http.WinHttpHandler.csproj |  12 +--
 ....Net.Http.WinHttpHandler.Unit.Tests.csproj |   2 +-
 .../ref/System.Net.Http.csproj                |   2 +-
 .../src/System.Net.Http.csproj                |  83 ++++++--------
 .../System.Net.Http.Functional.Tests.csproj   |  25 +++--
 .../System.Net.Http.Unit.Tests.csproj         |  12 +--
 .../ref/System.Net.HttpListener.csproj        |   2 +-
 .../src/System.Net.HttpListener.csproj        |  12 ++-
 .../ref/System.Net.Mail.csproj                |   2 +-
 .../src/System.Net.Mail.csproj                |  14 +--
 .../Unit/System.Net.Mail.Unit.Tests.csproj    |   8 +-
 .../ref/System.Net.NameResolution.csproj      |   2 +-
 .../src/System.Net.NameResolution.csproj      |   8 +-
 ...System.Net.NameResolution.Pal.Tests.csproj |   8 +-
 .../ref/System.Net.NetworkInformation.csproj  |   2 +-
 .../src/System.Net.NetworkInformation.csproj  |  30 +++---
 .../ref/System.Net.Ping.csproj                |   2 +-
 .../src/System.Net.Ping.csproj                |  18 ++--
 .../ref/System.Net.Primitives.csproj          |   2 +-
 .../src/System.Net.Primitives.csproj          |   8 +-
 .../System.Net.Primitives.Pal.Tests.csproj    |   8 +-
 ...stem.Net.Primitives.UnitTests.Tests.csproj |   4 +-
 .../ref/System.Net.Quic.csproj                |   2 +-
 .../src/System.Net.Quic.csproj                |  25 +++--
 .../ref/System.Net.Requests.csproj            |   2 +-
 .../src/System.Net.Requests.csproj            |   6 +-
 .../ref/System.Net.Security.csproj            |   2 +-
 .../src/System.Net.Security.csproj            |  36 +++----
 .../System.Net.Security.Tests.csproj          |   8 +-
 .../System.Net.Security.Unit.Tests.csproj     |   6 +-
 .../ref/System.Net.ServicePoint.csproj        |   2 +-
 .../src/System.Net.ServicePoint.csproj        |   2 +-
 .../ref/System.Net.Sockets.csproj             |   2 +-
 .../src/System.Net.Sockets.csproj             |  12 ++-
 .../System.Net.Sockets.Tests.csproj           |   2 +-
 .../ref/System.Net.WebClient.csproj           |   2 +-
 .../src/System.Net.WebClient.csproj           |   5 +-
 .../ref/System.Net.WebHeaderCollection.csproj |   2 +-
 .../src/System.Net.WebHeaderCollection.csproj |   2 +-
 .../ref/System.Net.WebProxy.csproj            |   2 +-
 .../src/System.Net.WebProxy.csproj            |   4 +-
 .../ref/System.Net.WebSockets.Client.csproj   |   2 +-
 .../src/System.Net.WebSockets.Client.csproj   |  10 +-
 .../ref/System.Net.WebSockets.csproj          |   2 +-
 .../src/System.Net.WebSockets.csproj          |   4 +-
 .../ref/System.Numerics.Vectors.csproj        |   2 +-
 .../src/System.Numerics.Vectors.csproj        |   2 +-
 .../ref/System.ObjectModel.csproj             |   2 +-
 .../src/System.ObjectModel.csproj             |   2 +-
 ...m.Private.DataContractSerialization.csproj |   2 +-
 .../src/System.Private.Uri.csproj             |   4 +-
 .../src/System.Private.Xml.Linq.csproj        |   2 +-
 .../src/System.Private.Xml.csproj             |   4 +-
 .../System.Reflection.DispatchProxy.csproj    |   2 +-
 .../System.Reflection.DispatchProxy.csproj    |   2 +-
 ...System.Reflection.Emit.ILGeneration.csproj |   2 +-
 ...System.Reflection.Emit.ILGeneration.csproj |   2 +-
 .../System.Reflection.Emit.Lightweight.csproj |   2 +-
 .../System.Reflection.Emit.Lightweight.csproj |   2 +-
 .../ref/System.Reflection.Emit.csproj         |   2 +-
 .../src/System.Reflection.Emit.csproj         |   2 +-
 .../ref/System.Reflection.Extensions.csproj   |   2 +-
 .../src/System.Reflection.Extensions.csproj   |   2 +-
 .../ref/System.Reflection.Primitives.csproj   |   2 +-
 .../src/System.Reflection.Primitives.csproj   |   2 +-
 .../System.Reflection.TypeExtensions.csproj   |   2 +-
 .../System.Reflection.TypeExtensions.csproj   |   2 +-
 .../ref/System.Reflection.csproj              |   2 +-
 .../src/System.Reflection.csproj              |   2 +-
 .../System.Resources.Extensions.Tests.csproj  |   2 +-
 .../ref/System.Resources.Reader.csproj        |   2 +-
 .../src/System.Resources.Reader.csproj        |   2 +-
 .../System.Resources.ResourceManager.csproj   |   2 +-
 .../System.Resources.ResourceManager.csproj   |   2 +-
 .../ref/System.Resources.Writer.csproj        |   2 +-
 .../src/System.Resources.Writer.csproj        |   2 +-
 .../src/System.Runtime.Caching.csproj         |   4 +-
 ...em.Runtime.CompilerServices.VisualC.csproj |   2 +-
 ...em.Runtime.CompilerServices.VisualC.csproj |   2 +-
 .../ref/System.Runtime.Experimental.csproj    |   2 +-
 .../ref/System.Runtime.Extensions.csproj      |   2 +-
 .../src/System.Runtime.Extensions.csproj      |   2 +-
 .../System.Runtime.Extensions.Tests.csproj    |   8 +-
 .../ref/System.Runtime.Handles.csproj         |   2 +-
 .../src/System.Runtime.Handles.csproj         |   2 +-
 ....InteropServices.RuntimeInformation.csproj |   2 +-
 ....InteropServices.RuntimeInformation.csproj |   2 +-
 .../ref/System.Runtime.InteropServices.csproj |   2 +-
 .../src/System.Runtime.InteropServices.csproj |   2 +-
 ...ystem.Runtime.InteropServices.Tests.csproj |  46 ++++----
 .../ref/System.Runtime.Intrinsics.csproj      |   2 +-
 .../src/System.Runtime.Intrinsics.csproj      |   2 +-
 .../ref/System.Runtime.Loader.csproj          |   2 +-
 .../src/System.Runtime.Loader.csproj          |   2 +-
 .../ref/System.Runtime.Numerics.csproj        |   2 +-
 .../src/System.Runtime.Numerics.csproj        |   2 +-
 ...em.Runtime.Serialization.Formatters.csproj |   2 +-
 ...em.Runtime.Serialization.Formatters.csproj |  20 ++--
 ...time.Serialization.Formatters.Tests.csproj |   4 +-
 .../System.Runtime.Serialization.Json.csproj  |   2 +-
 .../System.Runtime.Serialization.Json.csproj  |   2 +-
 ...em.Runtime.Serialization.Primitives.csproj |   2 +-
 ...em.Runtime.Serialization.Primitives.csproj |   2 +-
 .../System.Runtime.Serialization.Xml.csproj   |   2 +-
 .../System.Runtime.Serialization.Xml.csproj   |   2 +-
 .../System.Runtime/ref/System.Runtime.csproj  |   2 +-
 .../System.Runtime/src/System.Runtime.csproj  |   2 +-
 .../tests/System.Runtime.Tests.csproj         |   2 +-
 .../ref/System.Security.AccessControl.csproj  |   2 +-
 .../src/System.Security.AccessControl.csproj  |   5 +-
 .../ref/System.Security.Claims.csproj         |   2 +-
 .../src/System.Security.Claims.csproj         |   2 +-
 ...em.Security.Cryptography.Algorithms.csproj |   2 +-
 ...em.Security.Cryptography.Algorithms.csproj |   2 +-
 .../System.Security.Cryptography.Cng.csproj   |   2 +-
 .../System.Security.Cryptography.Cng.csproj   |   2 +-
 ...tem.Security.Cryptography.Cng.Tests.csproj |  12 +--
 .../System.Security.Cryptography.Csp.csproj   |   2 +-
 .../System.Security.Cryptography.Csp.csproj   |   2 +-
 ...stem.Security.Cryptography.Encoding.csproj |   2 +-
 ...stem.Security.Cryptography.Encoding.csproj |   2 +-
 ...ystem.Security.Cryptography.OpenSsl.csproj |   2 +-
 ...ystem.Security.Cryptography.OpenSsl.csproj |   2 +-
 ...Security.Cryptography.OpenSsl.Tests.csproj |   2 +-
 .../System.Security.Cryptography.Pkcs.csproj  |  47 ++++----
 ...em.Security.Cryptography.Pkcs.Tests.csproj |   2 +-
 ...em.Security.Cryptography.Primitives.csproj |   2 +-
 ...em.Security.Cryptography.Primitives.csproj |   2 +-
 ...Security.Cryptography.ProtectedData.csproj |   7 +-
 ...urity.Cryptography.X509Certificates.csproj |   2 +-
 ...urity.Cryptography.X509Certificates.csproj |   2 +-
 ...Cryptography.X509Certificates.Tests.csproj |  16 +--
 .../ref/System.Security.Cryptography.csproj   |   2 +-
 .../src/System.Security.Cryptography.csproj   |  30 +++---
 .../System.Security.Cryptography.Tests.csproj |   8 +-
 .../System.Security.Permissions.Tests.csproj  |   2 +-
 .../System.Security.Principal.Windows.csproj  |   2 +-
 .../System.Security.Principal.Windows.csproj  |  11 +-
 .../ref/System.Security.Principal.csproj      |   2 +-
 .../src/System.Security.Principal.csproj      |   2 +-
 .../ref/System.Security.SecureString.csproj   |   2 +-
 .../src/System.Security.SecureString.csproj   |   2 +-
 ...em.ServiceProcess.ServiceController.csproj |   5 +-
 .../System.Speech/src/System.Speech.csproj    |  12 ++-
 .../src/System.Text.Encoding.CodePages.csproj |   4 +-
 .../System.Text.Encoding.Extensions.csproj    |   2 +-
 .../System.Text.Encoding.Extensions.csproj    |   2 +-
 .../ref/System.Text.Encoding.csproj           |   2 +-
 .../src/System.Text.Encoding.csproj           |   2 +-
 .../src/System.Text.Encodings.Web.csproj      |   3 +-
 .../GenDefinedCharList.csproj                 |   2 +-
 .../GenUnicodeRanges/GenUnicodeRanges.csproj  |   2 +-
 .../System.Text.Json.SourceGeneration.targets |   2 +-
 ...m.Text.RegularExpressions.Generator.csproj |   2 +-
 .../ref/System.Text.RegularExpressions.csproj |   2 +-
 .../src/System.Text.RegularExpressions.csproj |   2 +-
 .../src/System.Threading.AccessControl.csproj |   5 +-
 .../ref/System.Threading.Overlapped.csproj    |   2 +-
 .../src/System.Threading.Overlapped.csproj    |   2 +-
 .../System.Threading.Tasks.Extensions.csproj  |   2 +-
 .../System.Threading.Tasks.Extensions.csproj  |   2 +-
 .../System.Threading.Tasks.Parallel.csproj    |   2 +-
 .../System.Threading.Tasks.Parallel.csproj    |   2 +-
 .../ref/System.Threading.Tasks.csproj         |   2 +-
 .../src/System.Threading.Tasks.csproj         |   2 +-
 .../ref/System.Threading.Thread.csproj        |   2 +-
 .../src/System.Threading.Thread.csproj        |   2 +-
 .../ref/System.Threading.ThreadPool.csproj    |   2 +-
 .../src/System.Threading.ThreadPool.csproj    |   2 +-
 .../ref/System.Threading.Timer.csproj         |   2 +-
 .../src/System.Threading.Timer.csproj         |   2 +-
 .../ref/System.Threading.csproj               |   2 +-
 .../src/System.Threading.csproj               |   2 +-
 .../ref/System.Transactions.Local.csproj      |   2 +-
 .../src/System.Transactions.Local.csproj      |   2 +-
 .../ref/System.ValueTuple.csproj              |   2 +-
 .../src/System.ValueTuple.csproj              |   2 +-
 .../ref/System.Web.HttpUtility.csproj         |   2 +-
 .../src/System.Web.HttpUtility.csproj         |   2 +-
 .../src/System.Windows.Extensions.csproj      |   9 +-
 .../System.Windows.Extensions.Tests.csproj    |   2 +-
 .../ref/System.Xml.ReaderWriter.csproj        |   2 +-
 .../src/System.Xml.ReaderWriter.csproj        |   2 +-
 .../ref/System.Xml.XDocument.csproj           |   2 +-
 .../src/System.Xml.XDocument.csproj           |   2 +-
 .../ref/System.Xml.XPath.XDocument.csproj     |   2 +-
 .../src/System.Xml.XPath.XDocument.csproj     |   2 +-
 .../ref/System.Xml.XPath.csproj               |   2 +-
 .../src/System.Xml.XPath.csproj               |   2 +-
 .../ref/System.Xml.XmlDocument.csproj         |   2 +-
 .../src/System.Xml.XmlDocument.csproj         |   2 +-
 .../ref/System.Xml.XmlSerializer.csproj       |   2 +-
 .../src/System.Xml.XmlSerializer.csproj       |   2 +-
 src/libraries/externals.csproj                |   2 +-
 src/libraries/native-binplace.proj            |   1 -
 src/libraries/pretest.proj                    |   2 +-
 src/libraries/ref.proj                        |   7 ++
 src/libraries/sendtohelix.proj                |  12 +--
 src/libraries/sendtohelixhelp.proj            |  15 ++-
 .../shims/generated/Directory.Build.props     |   2 +-
 .../shims/manual/Directory.Build.props        |   2 +-
 src/libraries/src.proj                        |   9 +-
 349 files changed, 931 insertions(+), 924 deletions(-)
 create mode 100644 eng/TraversalSdk.AfterTargets.targets
 delete mode 100644 eng/targetframeworksuffix.props

diff --git a/Directory.Build.props b/Directory.Build.props
index d862ee091fe81..b9cc1470bb780 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -305,5 +305,6 @@
   <PropertyGroup>
     <CustomBeforeNoTargets>$(RepositoryEngineeringDir)NoTargetsSdk.BeforeTargets.targets</CustomBeforeNoTargets>
     <CustomAfterTraversalProps>$(RepositoryEngineeringDir)TraversalSdk.AfterProps.props</CustomAfterTraversalProps>
+    <CustomAfterTraversalTargets>$(RepositoryEngineeringDir)TraversalSdk.AfterTargets.targets</CustomAfterTraversalTargets>
   </PropertyGroup>
 </Project>
diff --git a/docs/coding-guidelines/project-guidelines.md b/docs/coding-guidelines/project-guidelines.md
index 5f27836900e25..486a0afd09137 100644
--- a/docs/coding-guidelines/project-guidelines.md
+++ b/docs/coding-guidelines/project-guidelines.md
@@ -22,7 +22,7 @@ Below is a list of all the various options we pivot the project builds on:
 ## Individual build properties
 The following are the properties associated with each build pivot
 
-- `$(BuildTargetFramework) -> Any .NETCoreApp or .NETFramework TFM, e.g. net5.0`
+- `$(BuildTargetFramework) -> Any .NETCoreApp or .NETFramework TFM, e.g. net7.0`
 - `$(TargetOS) -> Windows | Linux | OSX | FreeBSD | [defaults to running OS when empty]`
 - `$(Configuration) -> Release | [defaults to Debug when empty]`
 - `$(TargetArchitecture) - x86 | x64 | arm | arm64 | [defaults to x64 when empty]`
@@ -37,22 +37,18 @@ Each project will define a set of supported TargetFrameworks
 <PropertyGroup>
 ```
 
-- `$(BuildSettings) -> $(BuildTargetFramework)[-$(TargetOS)][-$(Configuration)][-$(TargetArchitecture)]`
- - Note this property should be file path safe and thus can be used in file names or directories that need to a unique path for a project configuration.
- - The only required Build Settings value is the `$(BuildTargetFramework)` the others are optional.
-
 Example:
-Pure netstandard configuration:
+Non cross-targeting project that targets .NETStandard:
 ```
 <PropertyGroup>
-  <TargetFrameworks>netstandard2.0</TargetFrameworks>
+  <TargetFramework>netstandard2.0</TargetFramework>
 <PropertyGroup>
 ```
 
-All supported targets with unique windows/unix build for netcoreapp:
+A cross-targeting project which targets specific platform with `$(NetCoreAppCurrent)` and one .NETFramework tfm:
 ```
 <PropertyGroup>
-  <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetFrameworkCurrent)</TargetFrameworks>
+  <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetFrameworkMinimum)</TargetFrameworks>
 <PropertyGroup>
 ```
 
@@ -61,15 +57,15 @@ All supported targets with unique windows/unix build for netcoreapp:
 A full or individual project build is centered around BuildTargetFramework, TargetOS, Configuration and TargetArchitecture.
 
 1. `$(BuildTargetFramework), $(TargetOS), $(Configuration), $(TargetArchitecture)` can individually be passed in to change the default values.
-2. If nothing is passed to the build then we will default value of these properties from the environment. Example: `net5.0-[TargetOS Running On]-Debug-x64`.
-3. While Building an individual project from the VS, we build the project for all latest netcoreapp target frameworks.
+2. If nothing is passed to the build then we will default value of these properties from the environment. Example: `net7.0-[TargetOS Running On]-Debug-x64`.
+3. When building an individual project (either from the CLI or an IDE), all target frameworks are built.
 
 We also have `RuntimeOS` which can be passed to customize the specific OS and version needed for native package builds as well as package restoration. If not passed it will default based on the OS you are running on.
 
-Any of the mentioned properties can be set via `/p:<Property>=<Value>` at the command line. When building using our run tool or any of the wrapper scripts around it (i.e. build.cmd) a number of these properties have aliases which make them easier to pass (run build.cmd/sh -? for the aliases).
+Any of the mentioned properties can be set via `/p:<Property>=<Value>` at the command line. When building using any of the wrapper scripts around it (i.e. build.cmd) a number of these properties have aliases which make them easier to pass (run build.cmd/sh -? for the aliases).
 
 ## Selecting the correct BuildSettings
-When building an individual project the `BuildTargetFramework` and `TargetOS` will be used to select the closest matching TargetFramework listed in the projects `TargetFrameworks` property. The rules used to select the targetFramework will consider compatible target frameworks and OS fallbacks.
+When building an individual project the `BuildTargetFramework` and `TargetOS` will be used to select the compatible dependencies which are expressed as ProjectReference items.
 
 ## Supported full build settings
 - .NET Core latest on current OS (default) -> `$(NetCoreAppCurrent)-[RunningOS]`
@@ -80,37 +76,64 @@ When building an individual project the `BuildTargetFramework` and `TargetOS` wi
 ## TargetFramework conditions
 `TargetFramework` conditions should be avoided in the first PropertyGroup as that causes DesignTimeBuild issues: https://github.com/dotnet/project-system/issues/6143
 
-1. Use an equality check if the TargetFramework isn't overloaded with the OS portion.
+1. Use TargetFrameworkIdentifier to condition on an entire framework to differentiate between .NETCoreApp, .NETStandard and .NETFramework.
+Example:
+```
+<PropertyGroup>
+  <TargetFrameworks>$(NetCoreAppCurrent);netstandard2.0;$(NetFrameworkMinimum)</TargetFrameworks>
+</PropertyGroup>
+<ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp'">...</ItemGroup>
+<ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETStandard'">...</ItemGroup>
+<ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework'">...</ItemGroup>
+```
+2. Use equality checks if you want to condition on specific runtime agnostic target frameworks (i.e. without the `-windows` suffix).
 Example:
 ```
 <PropertyGroup>
-  <TargetFrameworks>netstandard2.0;netstandard2.1</TargetFrameworks>
+  <TargetFrameworks>$(NetCoreAppCurrent);netstandard2.0;$(NetFrameworkMinimum)</TargetFrameworks>
 </PropertyGroup>
+<ItemGroup Condition="'$(TargetFramework)' == '$(NetCoreAppCurrent)'">...</ItemGroup>
 <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">...</ItemGroup>
+<ItemGroup Condition="'$(TargetFramework)' == '$(NetFrameworkMinimum)'">...</ItemGroup>
 ```
-2. Use a StartsWith when you want to test for multiple .NETStandard or .NETFramework versions.
+3. Use the `TargetPlatformIdentifier` property to condition on a .NETCoreApp platform specific target framework. Note that .NETStandard and .NETFramework target frameworks can't be platform specific.
 Example:
 ```
 <PropertyGroup>
-  <TargetFrameworks>netstandard2.0;netstandard2.1</TargetFrameworks>
+  <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-OSX;$(NetCoreAppCurrent)</TargetFrameworks>
+</PropertyGroup>
+<ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">...</ItemGroup>
+<ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'OSX'">...</ItemGroup>
+```
+Important: In contrast to the old `Targets*` checks, `TargetPlatformIdentifier` conditions apply to a single tfm only, inheritance between target frameworks can't be expressed. See the example below for Unix:
+```
+<PropertyGroup>
+  <TargetFrameworks>$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent)-Linux;$(NetCoreAppCurrent)-android;$(NetCoreAppCurrent)-windows</TargetFrameworks>
 </PropertyGroup>
-<ItemGroup Condition="$(TargetFramework.StartsWith('netstandard'))>...</ItemGroup>
+<ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Linux' or '$(TargetPlatformIdentifier)' == 'android'">...</ItemGroup>
+<!-- Negations make such conditions easier to write and read. -->
+<ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'windows'">...</ItemGroup>
 ```
-3. Use a StartsWith if the TargetFramework is overloaded with the OS portion.
+4. Set the `TargetPlatformIdentifier` property in the project to be able to condition on it in properties in the project file.
+That is necessary as the SDK sets the `TargetPlatformIdentifier` in a .targets file after the project is evaluated. Because of that, the property isn't available during the project's evaluation and must be set manually.
 Example:
 ```
 <PropertyGroup>
-  <TargetFrameworks>netstandard2.0-windows;netstandard2.0-Unix</TargetFrameworks>
+  <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-android</TargetFrameworks>
+</PropertyGroup>
+<!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
+<PropertyGroup>
+  <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+  <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'android'">$(DefineConstants);ANDROID_USE_BUFFER</DefineConstants>
 </PropertyGroup>
-<ItemGroup Condition="$(TargetFramework.StartsWith('netstandard2.0'))>...</ItemGroup>
 ```
-4. Use negations if that makes the conditions easier.
+5. Use negations if that makes the conditions easier.
 Example:
 ```
 <PropertyGroup>
-  <TargetFrameworks>netstandard2.0;net462;net472;net5.0</TargetFrameworks>
+  <TargetFrameworks>$(NetCoreAppCurrent);netstandard2.0;net462</TargetFrameworks>
 </PropertyGroup>
-<ItemGroup Condition="!$(TargetFramework.StartsWith('net4'))>...</ItemGroup>
+<ItemGroup Condition="'$(TargetFrameworkIdentifier)' != '.NETFramework'">...</ItemGroup>
 <ItemGroup Condition="'$(TargetFramework)' != 'netstandard2.0'">...</ItemGroup>
 ```
 
@@ -119,11 +142,10 @@ Example:
 Library projects should use the following directory layout.
 
 ```
-src\<Library Name>\src - Contains the source code for the library.
+src\<Library Name>\gen - Contains source code for the assembly's source generator.
 src\<Library Name>\ref - Contains any reference assembly projects for the library.
-src\<Library Name>\pkg - Contains package projects for the library.
+src\<Library Name>\src - Contains the source code for the library.
 src\<Library Name>\tests - Contains the test code for a library.
-src\<Library Name>\gen - Contains source code for the assembly's source generator.
 ```
 
 ## ref
diff --git a/eng/BeforeTargetFrameworkInference.targets b/eng/BeforeTargetFrameworkInference.targets
index 60b412845483f..70de3444b5893 100644
--- a/eng/BeforeTargetFrameworkInference.targets
+++ b/eng/BeforeTargetFrameworkInference.targets
@@ -1,5 +1,22 @@
 <Project>
 
-  <Import Project="$(MSBuildThisDirectory)targetframeworksuffix.props" Condition="'$(DesignTimeBuild)' == 'true'" />
+  <PropertyGroup>
+    <TargetPlatformSupported>true</TargetPlatformSupported>
+    <TargetPlatformVersionSupported>true</TargetPlatformVersionSupported>
+
+    <!-- Value of 0.0 produces versionless SupportedOSPlatform attribute.
+         This is required for platforms not expected to have a version,
+         and we currently omit the version for all platforms. -->
+    <SupportedOSPlatformVersion>0.0</SupportedOSPlatformVersion>
+
+    <!-- Disable setting a default Windows platform for .NETStandard and .NET Framework libraries.
+         This ensures that the TargetPlatformIdentifier property is empty for non .NETCoreApp tfms. -->
+    <_EnableDefaultWindowsPlatform>false</_EnableDefaultWindowsPlatform>
+    <_targetPlatformIdentifier Condition="$(TargetFramework.Contains('-'))">$(TargetFramework.SubString($([MSBuild]::Add($(TargetFramework.IndexOf('-')), 1))))</_targetPlatformIdentifier>
+  </PropertyGroup>
+
+  <PropertyGroup Condition="'$(_targetPlatformIdentifier)' != '' and '$(_targetPlatformIdentifier)' != 'windows'">
+    <TargetPlatformVersion>1.0</TargetPlatformVersion>
+  </PropertyGroup>
 
 </Project>
diff --git a/eng/TraversalSdk.AfterTargets.targets b/eng/TraversalSdk.AfterTargets.targets
new file mode 100644
index 0000000000000..f88c48dc8677d
--- /dev/null
+++ b/eng/TraversalSdk.AfterTargets.targets
@@ -0,0 +1,18 @@
+<Project>
+
+  <!-- Uses the Microsoft.DotNet.Build.Tasks.TargetFramework package to filter out target frameworks from ProjectReferences. -->
+  <PropertyGroup Condition="'$(FilterTraversalProjectReferences)' == 'true'">
+    <BuildDependsOn>$(BuildDependsOn);ResolveP2PReferences</BuildDependsOn>
+    <CleanDependsOn>$(CleanDependsOn);ResolveP2PReferences</CleanDependsOn>
+    <RebuildDependsOn>$(RebuildDependsOn);ResolveP2PReferences</RebuildDependsOn>
+    <TestDependsOn>$(TestDependsOn);ResolveP2PReferences</TestDependsOn>
+    <VSTestDependsOn>$(VSTestDependsOn);ResolveP2PReferences</VSTestDependsOn>
+    <PackDependsOn>$(PackDependsOn);ResolveP2PReferences</PackDependsOn>
+    <PublishDependsOn>$(PublishDependsOn);ResolveP2PReferences</PublishDependsOn>
+  </PropertyGroup>
+
+  <ItemGroup Condition="'$(FilterTraversalProjectReferences)' == 'true'">
+    <ProjectReference Update="@(ProjectReference)" SkipGetTargetFrameworkProperties="false" />
+  </ItemGroup>
+
+</Project>
\ No newline at end of file
diff --git a/eng/Version.Details.xml b/eng/Version.Details.xml
index ae6fdbb597200..05a44e0bf9d7b 100644
--- a/eng/Version.Details.xml
+++ b/eng/Version.Details.xml
@@ -102,9 +102,9 @@
       <Uri>https://github.com/dotnet/arcade</Uri>
       <Sha>78eaf78761027d225030be2b28aaf4e8bf392929</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.DotNet.Build.Tasks.TargetFramework" Version="7.0.0-beta.22110.7">
+    <Dependency Name="Microsoft.DotNet.Build.Tasks.TargetFramework" Version="7.0.0-beta.22111.10">
       <Uri>https://github.com/dotnet/arcade</Uri>
-      <Sha>78eaf78761027d225030be2b28aaf4e8bf392929</Sha>
+      <Sha>ff6cc4e9c3eef575f62a33a642ca80e79d27c9bb</Sha>
     </Dependency>
     <Dependency Name="Microsoft.DotNet.RemoteExecutor" Version="7.0.0-beta.22110.7">
       <Uri>https://github.com/dotnet/arcade</Uri>
diff --git a/eng/Versions.props b/eng/Versions.props
index e43cb18f09acd..3c0663f6dd162 100644
--- a/eng/Versions.props
+++ b/eng/Versions.props
@@ -67,7 +67,7 @@
     <MicrosoftDotNetBuildTasksArchivesVersion>7.0.0-beta.22110.7</MicrosoftDotNetBuildTasksArchivesVersion>
     <MicrosoftDotNetBuildTasksInstallersVersion>7.0.0-beta.22110.7</MicrosoftDotNetBuildTasksInstallersVersion>
     <MicrosoftDotNetBuildTasksPackagingVersion>7.0.0-beta.22110.7</MicrosoftDotNetBuildTasksPackagingVersion>
-    <MicrosoftDotNetBuildTasksTargetFrameworkVersion>7.0.0-beta.22110.7</MicrosoftDotNetBuildTasksTargetFrameworkVersion>
+    <MicrosoftDotNetBuildTasksTargetFrameworkVersion>7.0.0-beta.22111.10</MicrosoftDotNetBuildTasksTargetFrameworkVersion>
     <MicrosoftDotNetBuildTasksTemplatingVersion>7.0.0-beta.22110.7</MicrosoftDotNetBuildTasksTemplatingVersion>
     <MicrosoftDotNetBuildTasksWorkloadsPackageVersion>7.0.0-beta.22110.7</MicrosoftDotNetBuildTasksWorkloadsPackageVersion>
     <MicrosoftDotNetRemoteExecutorVersion>7.0.0-beta.22110.7</MicrosoftDotNetRemoteExecutorVersion>
diff --git a/eng/packaging.targets b/eng/packaging.targets
index e705b4e711011..fd2568f5d30cf 100644
--- a/eng/packaging.targets
+++ b/eng/packaging.targets
@@ -10,9 +10,9 @@
     <PackDependsOn>AddNETStandardCompatErrorFileForPackaging;IncludeAnalyzersInPackage;$(PackDependsOn)</PackDependsOn>
     <BeforePack>AddNETStandardCompatErrorFileForPackaging;IncludeAnalyzersInPackage;$(BeforePack)</BeforePack>
     <TargetsForTfmSpecificContentInPackage>$(TargetsForTfmSpecificContentInPackage);AddRuntimeSpecificFilesToPackage;IncludeProjectReferencesWithPackAttributeInPackage</TargetsForTfmSpecificContentInPackage>
-    <IncludeBuildOutput Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp' and '$(TargetPlatformIdentifier)' != ''">false</IncludeBuildOutput>
+    <IncludeBuildOutput Condition="'$(TargetPlatformIdentifier)' != ''">false</IncludeBuildOutput>
     <!-- Don't include target platform specific dependencies, since we use the target platform to represent RIDs instead -->
-    <SuppressDependenciesWhenPacking Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp' and '$(TargetPlatformIdentifier)' != ''">true</SuppressDependenciesWhenPacking>
+    <SuppressDependenciesWhenPacking Condition="'$(TargetPlatformIdentifier)' != ''">true</SuppressDependenciesWhenPacking>
     <PackageDesignerMarkerFile>$(MSBuildThisFileDirectory)useSharedDesignerContext.txt</PackageDesignerMarkerFile>
     <!-- Generate packages for rid specific projects or for allconfigurations during build. -->
     <!-- A package isn't generated if in servicing or in runtimelab. Intended to be overridden at project level. -->
@@ -101,7 +101,7 @@
                             DocumentationProjectOutputGroup;
                             SatelliteDllsProjectOutputGroup;
                             $(TargetsForTfmSpecificBuildOutput)"
-          Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp' and '$(TargetPlatformIdentifier)' != ''">
+          Condition="'$(TargetPlatformIdentifier)' != ''">
     <PropertyGroup>
       <RuntimeSymbolPath>$(TargetDir)$(TargetName).pdb</RuntimeSymbolPath>
       <_packageTargetRuntime>$(TargetPlatformIdentifier.ToLowerInvariant().Replace('windows', 'win'))</_packageTargetRuntime>
diff --git a/eng/targetframeworksuffix.props b/eng/targetframeworksuffix.props
deleted file mode 100644
index f7074fe3e199f..0000000000000
--- a/eng/targetframeworksuffix.props
+++ /dev/null
@@ -1,101 +0,0 @@
-<Project>
-
-  <PropertyGroup>
-    <TargetPlatformSupported>true</TargetPlatformSupported>
-    <TargetPlatformVersionSupported>true</TargetPlatformVersionSupported>
-
-    <!-- Value of 0.0 produces versionless SupportedOSPlatform attribute.
-         This is required for platforms not expected to have a version,
-         and we currently omit the version for all platforms. -->
-    <SupportedOSPlatformVersion>0.0</SupportedOSPlatformVersion>
-    <TargetPlatformIdentifier Condition="$(TargetFramework.Contains('-'))">$(TargetFramework.SubString($([MSBuild]::Add($(TargetFramework.IndexOf('-')), 1))))</TargetPlatformIdentifier>
-  </PropertyGroup>
-
-  <PropertyGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows'">
-    <TargetPlatformVersion>1.0</TargetPlatformVersion>
-  </PropertyGroup>
-
-  <Choose>
-    <When Condition="'$(TargetPlatformIdentifier)' == 'windows'">
-      <PropertyGroup>
-        <TargetsWindows>true</TargetsWindows>
-      </PropertyGroup>
-    </When>
-    <When Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
-      <PropertyGroup>
-        <TargetsUnix>true</TargetsUnix>
-      </PropertyGroup>
-    </When>
-    <When Condition="'$(TargetPlatformIdentifier)' == 'Linux'">
-      <PropertyGroup>
-        <TargetsUnix>true</TargetsUnix>
-        <TargetsLinux>true</TargetsLinux>
-      </PropertyGroup>
-    </When>
-    <When Condition="'$(TargetPlatformIdentifier)' == 'Android'">
-      <PropertyGroup>
-        <TargetsUnix>true</TargetsUnix>
-        <TargetsLinux>true</TargetsLinux>
-        <TargetsAndroid>true</TargetsAndroid>
-      </PropertyGroup>
-    </When>
-    <When Condition="'$(TargetPlatformIdentifier)' == 'OSX'">
-      <PropertyGroup>
-        <TargetsUnix>true</TargetsUnix>
-        <TargetsOSX>true</TargetsOSX>
-      </PropertyGroup>
-    </When>
-    <When Condition="'$(TargetPlatformIdentifier)' == 'MacCatalyst'">
-      <PropertyGroup>
-        <TargetsUnix>true</TargetsUnix>
-        <TargetsMacCatalyst>true</TargetsMacCatalyst>
-      </PropertyGroup>
-    </When>
-    <When Condition="'$(TargetPlatformIdentifier)' == 'tvOS'">
-      <PropertyGroup>
-        <TargetsUnix>true</TargetsUnix>
-        <TargetstvOS>true</TargetstvOS>
-      </PropertyGroup>
-    </When>
-    <When Condition="'$(TargetPlatformIdentifier)' == 'iOS'">
-      <PropertyGroup>
-        <TargetsUnix>true</TargetsUnix>
-        <TargetsiOS>true</TargetsiOS>
-      </PropertyGroup>
-    </When>
-    <When Condition="'$(TargetPlatformIdentifier)' == 'FreeBSD'">
-      <PropertyGroup>
-        <TargetsUnix>true</TargetsUnix>
-        <TargetsFreeBSD>true</TargetsFreeBSD>
-      </PropertyGroup>
-    </When>
-    <When Condition="'$(TargetPlatformIdentifier)' == 'NetBSD'">
-      <PropertyGroup>
-        <TargetsUnix>true</TargetsUnix>
-        <TargetsNetBSD>true</TargetsNetBSD>
-      </PropertyGroup>
-    </When>
-    <When Condition="'$(TargetPlatformIdentifier)' == 'illumos'">
-      <PropertyGroup>
-        <TargetsUnix>true</TargetsUnix>
-        <Targetsillumos>true</Targetsillumos>
-      </PropertyGroup>
-    </When>
-    <When Condition="'$(TargetPlatformIdentifier)' == 'Solaris'">
-      <PropertyGroup>
-        <TargetsUnix>true</TargetsUnix>
-        <TargetsSolaris>true</TargetsSolaris>
-      </PropertyGroup>
-    </When>
-    <When Condition="'$(TargetPlatformIdentifier)' == 'Browser'">
-      <PropertyGroup>
-        <TargetsBrowser>true</TargetsBrowser>
-      </PropertyGroup>
-    </When>
-    <When Condition="'$(TargetPlatformIdentifier)' == ''">
-      <PropertyGroup>
-        <TargetsAnyOS>true</TargetsAnyOS>
-      </PropertyGroup>
-    </When>
-  </Choose>
-</Project>
diff --git a/eng/testing/tests.props b/eng/testing/tests.props
index f23f4cc62e956..e91ec1bbcf0e3 100644
--- a/eng/testing/tests.props
+++ b/eng/testing/tests.props
@@ -34,8 +34,8 @@
 
   <!-- Provide runtime options to Mono (interpreter, aot, debugging, etc) -->
   <ItemGroup Condition="'$(MonoEnvOptions)' != '' and '$(TargetsMobile)' != 'true'">
-    <RunScriptCommands Condition="'$(TargetsWindows)' == 'true'" Include="set MONO_ENV_OPTIONS='$(MonoEnvOptions)'" />
-    <RunScriptCommands Condition="'$(TargetsWindows)' != 'true'" Include="export MONO_ENV_OPTIONS='$(MonoEnvOptions)'" />
+    <RunScriptCommands Condition="'$(TargetsWindows)' == 'true' or '$(TargetPlatformIdentifier)' == 'windows'" Include="set MONO_ENV_OPTIONS='$(MonoEnvOptions)'" />
+    <RunScriptCommands Condition="'$(TargetsWindows)' != 'true' and '$(TargetPlatformIdentifier)' != 'windows'" Include="export MONO_ENV_OPTIONS='$(MonoEnvOptions)'" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(TestRunRequiresLiveRefPack)' == 'true'">
diff --git a/eng/versioning.targets b/eng/versioning.targets
index 4dacec01a8686..37e9eba03cd60 100644
--- a/eng/versioning.targets
+++ b/eng/versioning.targets
@@ -25,8 +25,8 @@
     </AssemblyMetadata>
   </ItemGroup>
 
-  <PropertyGroup Condition="'$(TargetsAnyOS)' == 'true' and !$(TargetFrameworks.Contains('$(TargetFramework)-Browser'))">
-      <CrossPlatformAndHasNoBrowserTarget>true</CrossPlatformAndHasNoBrowserTarget>
+  <PropertyGroup Condition="'$(TargetPlatformIdentifier)' == '' and !$(TargetFrameworks.Contains('$(TargetFramework)-Browser'))">
+    <CrossPlatformAndHasNoBrowserTarget>true</CrossPlatformAndHasNoBrowserTarget>
   </PropertyGroup>
 
   <!-- Enables warnings for Android, iOS, tvOS and macCatalyst for all builds -->
@@ -38,16 +38,18 @@
   </ItemGroup>
 
   <!-- Enables browser warnings for cross platform or Browser targeted builds -->
-  <ItemGroup Condition="('$(TargetsBrowser)' == 'true' or '$(CrossPlatformAndHasNoBrowserTarget)' == 'true') and '$(IsTestProject)' != 'true'">
+  <ItemGroup Condition="('$(TargetPlatformIdentifier)' == 'Browser' or '$(CrossPlatformAndHasNoBrowserTarget)' == 'true') and '$(IsTestProject)' != 'true'">
     <SupportedPlatform Include="browser"/>
   </ItemGroup>
 
   <!-- Add target platforms into MSBuild SupportedPlatform list -->
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true' and '$(IsTestProject)' != 'true'">
-    <SupportedPlatform Condition="'$(Targetsillumos)' == 'true'" Include="illumos"/>
-    <SupportedPlatform Condition="'$(TargetsSolaris)' == 'true'" Include="Solaris"/>
-    <SupportedPlatform Condition="'$(TargetstvOS)' == 'true'" Include="tvOS"/>
-    <SupportedPlatform Condition="'$(TargetsUnix)' == 'true'" Include="Unix"/>
+  <ItemGroup Condition="'$(IsTestProject)' != 'true'">
+    <SupportedPlatform Condition="'$(TargetPlatformIdentifier)' == 'illumos'" Include="illumos" />
+    <SupportedPlatform Condition="'$(TargetPlatformIdentifier)' == 'Solaris'" Include="Solaris" />
+    <SupportedPlatform Condition="'$(TargetPlatformIdentifier)' == 'tvOS'" Include="tvOS" />
+    <SupportedPlatform Condition="'$(TargetPlatformIdentifier)' != '' and
+                                  '$(TargetPlatformIdentifier)' != 'Browser' and
+                                  '$(TargetPlatformIdentifier)' != 'windows'" Include="Unix" />
   </ItemGroup>
 
   <!-- Adds UnsupportedOSPlatform and SupportedOSPlatform attributes to the assembly when:
@@ -55,8 +57,10 @@
       * This is a cross-platform target
       * The build isn't targeting .NET Framework
     -->
-  <Target Name="AddOSPlatformAttributes" BeforeTargets="GenerateAssemblyInfo" AfterTargets="PrepareForBuild"
-    Condition="'$(TargetsAnyOS)' == 'true' and '$(IsTestProject)' != 'true' and '$(TargetFrameworkIdentifier)' != '.NETFramework'">
+  <Target Name="AddOSPlatformAttributes"
+          BeforeTargets="GenerateAssemblyInfo"
+          AfterTargets="PrepareForBuild"
+          Condition="'$(TargetPlatformIdentifier)' == '' and '$(IsTestProject)' != 'true' and '$(TargetFrameworkIdentifier)' != '.NETFramework'">
     <!-- Defensively de-dupe the values -->
     <ItemGroup>
       <_unsupportedOSPlatforms Include="$(UnsupportedOSPlatforms)" />
@@ -85,7 +89,7 @@
   </Target>
 
   <!-- Add PlatformNeutralAssembly property for targeted builds of cross platform assemblies -->
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true' and '$(IsTestProject)' != 'true' and '@(SupportedOSPlatforms)' == ''">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(IsTestProject)' != 'true' and '@(SupportedOSPlatforms)' == ''">
     <CompilerVisibleProperty Include="PlatformNeutralAssembly" />
   </ItemGroup>
 
diff --git a/src/libraries/Common/tests/Common.Tests.csproj b/src/libraries/Common/tests/Common.Tests.csproj
index 24841a2dedcf7..0dc2a91ebd82f 100644
--- a/src/libraries/Common/tests/Common.Tests.csproj
+++ b/src/libraries/Common/tests/Common.Tests.csproj
@@ -112,7 +112,7 @@
     <Compile Include="$(CommonPath)System\Net\MultiArrayBuffer.cs" Link="Common\System\Net\MultiArrayBuffer.cs" />
     <Compile Include="$(CommonPath)System\Net\StreamBuffer.cs" Link="Common\System\Net\StreamBuffer.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)'=='true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)System\IO\PathInternal.Windows.cs"
              Link="System\IO\PathInternal.Windows.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
@@ -128,7 +128,7 @@
     <Compile Include="$(CoreLibSharedDir)System\PasteArguments.Windows.cs"
              Link="System\PasteArguments.Windows.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'windows'">
     <Compile Include="Tests\System\IO\PathInternal.Unix.Tests.cs" />
     <Compile Include="$(CommonPath)System\IO\PathInternal.Unix.cs"
              Link="System\IO\PathInternal.Unix.cs" />
@@ -140,12 +140,12 @@
              Link="System\PasteArguments.Unix.cs" />
   </ItemGroup>
   <!-- Linux specific files -->
-  <ItemGroup Condition="'$(TargetsLinux)' == 'true' or '$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Linux' or '$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="$(CommonPath)Interop\Linux\Interop.Libraries.cs"
              Link="Common\Interop\Linux\Interop.Libraries.cs" />
   </ItemGroup>
   <!-- OSX specific files -->
-  <ItemGroup Condition=" '$(TargetsOSX)' == 'true' ">
+  <ItemGroup Condition=" '$(TargetPlatformIdentifier)' == 'OSX' ">
     <Compile Include="$(CommonPath)Interop\OSX\Interop.Libraries.cs"
              Link="Common\Interop\OSX\Interop.Libraries.cs" />
   </ItemGroup>
diff --git a/src/libraries/Directory.Build.props b/src/libraries/Directory.Build.props
index 7858515cfc41d..961c33028eab1 100644
--- a/src/libraries/Directory.Build.props
+++ b/src/libraries/Directory.Build.props
@@ -66,7 +66,6 @@
 
   <Import Project="NetCoreAppLibrary.props" />
   <Import Project="$(RepositoryEngineeringDir)referenceAssemblies.props" Condition="'$(IsReferenceAssembly)' == 'true'" />
-  <Import Project="$(RepositoryEngineeringDir)targetframeworksuffix.props" Condition="'$(DesignTimeBuild)' != 'true'" />
 
   <PropertyGroup>
     <!-- Default any assembly not specifying a key to use the Open Key -->
diff --git a/src/libraries/Microsoft.CSharp/ref/Microsoft.CSharp.csproj b/src/libraries/Microsoft.CSharp/ref/Microsoft.CSharp.csproj
index 739cd0edbbe8a..eede850861ac6 100644
--- a/src/libraries/Microsoft.CSharp/ref/Microsoft.CSharp.csproj
+++ b/src/libraries/Microsoft.CSharp/ref/Microsoft.CSharp.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/Microsoft.CSharp/src/Microsoft.CSharp.csproj b/src/libraries/Microsoft.CSharp/src/Microsoft.CSharp.csproj
index 8f9de151dfdab..b41b3ec1f9321 100644
--- a/src/libraries/Microsoft.CSharp/src/Microsoft.CSharp.csproj
+++ b/src/libraries/Microsoft.CSharp/src/Microsoft.CSharp.csproj
@@ -4,14 +4,16 @@
     <Nullable>enable</Nullable>
     <NoWarn>$(NoWarn);nullable</NoWarn>
   </PropertyGroup>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <EnableComBinder Condition="'$(TargetsWindows)'=='true'">true</EnableComBinder>
-    <DefineConstants Condition="'$(EnableComBinder)'=='true'">$(DefineConstants);ENABLECOMBINDER</DefineConstants>
-    <AllowUnsafeBlocks Condition="'$(EnableComBinder)'=='true'">true</AllowUnsafeBlocks>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <EnableComBinder Condition="'$(TargetPlatformIdentifier)' == 'windows'">true</EnableComBinder>
+    <DefineConstants Condition="'$(EnableComBinder)' == 'true'">$(DefineConstants);ENABLECOMBINDER</DefineConstants>
+    <AllowUnsafeBlocks Condition="'$(EnableComBinder)' == 'true'">true</AllowUnsafeBlocks>
   </PropertyGroup>
   <ItemGroup>
     <ILLinkDescriptorsXmls Include="$(ILLinkDirectory)ILLink.Descriptors.Shared.xml" />
-    <ILLinkDescriptorsXmls Condition="'$(TargetsWindows)' == 'true'" Include="$(ILLinkDirectory)ILLink.Descriptors.Windows.xml" />
+    <ILLinkDescriptorsXmls Condition="'$(TargetPlatformIdentifier)' == 'windows'" Include="$(ILLinkDirectory)ILLink.Descriptors.Windows.xml" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="Microsoft\CSharp\RuntimeBinder\ArgumentObject.cs" />
diff --git a/src/libraries/Microsoft.Extensions.Hosting.Systemd/src/Microsoft.Extensions.Hosting.Systemd.csproj b/src/libraries/Microsoft.Extensions.Hosting.Systemd/src/Microsoft.Extensions.Hosting.Systemd.csproj
index b9faefd40f2f0..1e2a601e8065f 100644
--- a/src/libraries/Microsoft.Extensions.Hosting.Systemd/src/Microsoft.Extensions.Hosting.Systemd.csproj
+++ b/src/libraries/Microsoft.Extensions.Hosting.Systemd/src/Microsoft.Extensions.Hosting.Systemd.csproj
@@ -10,11 +10,11 @@
     <IsPackable>true</IsPackable>
   </PropertyGroup>
 
-  <ItemGroup Condition="!$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net6.0'))">
+  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'">
     <Compile Remove="SystemdLifetime.netcoreapp.cs" />
   </ItemGroup>
 
-  <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net6.0'))">
+  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp'">
     <Compile Remove="SystemdLifetime.netstandard.cs" />
   </ItemGroup>
 
diff --git a/src/libraries/Microsoft.Extensions.Logging.Abstractions/gen/Microsoft.Extensions.Logging.Generators.targets b/src/libraries/Microsoft.Extensions.Logging.Abstractions/gen/Microsoft.Extensions.Logging.Generators.targets
index 77a182fa4649a..768d626074be8 100644
--- a/src/libraries/Microsoft.Extensions.Logging.Abstractions/gen/Microsoft.Extensions.Logging.Generators.targets
+++ b/src/libraries/Microsoft.Extensions.Logging.Abstractions/gen/Microsoft.Extensions.Logging.Generators.targets
@@ -1,7 +1,7 @@
 <Project>
 
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0</TargetFrameworks>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <AssemblyName>$(MSBuildThisFileName)</AssemblyName>
     <RootNamespace>$(MSBuildThisFileName)</RootNamespace>
     <StringResourcesClassName>SR</StringResourcesClassName>
diff --git a/src/libraries/Microsoft.VisualBasic.Core/ref/Microsoft.VisualBasic.Core.csproj b/src/libraries/Microsoft.VisualBasic.Core/ref/Microsoft.VisualBasic.Core.csproj
index 7eba5c85af492..e2aa9431990aa 100644
--- a/src/libraries/Microsoft.VisualBasic.Core/ref/Microsoft.VisualBasic.Core.csproj
+++ b/src/libraries/Microsoft.VisualBasic.Core/ref/Microsoft.VisualBasic.Core.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/Microsoft.VisualBasic.Core/src/Microsoft.VisualBasic.Core.vbproj b/src/libraries/Microsoft.VisualBasic.Core/src/Microsoft.VisualBasic.Core.vbproj
index cdc18e0dd4391..060ab1a99b1a7 100644
--- a/src/libraries/Microsoft.VisualBasic.Core/src/Microsoft.VisualBasic.Core.vbproj
+++ b/src/libraries/Microsoft.VisualBasic.Core/src/Microsoft.VisualBasic.Core.vbproj
@@ -9,19 +9,21 @@
     <OptionCompare>Binary</OptionCompare>
     <WarningsNotAsErrors>42025</WarningsNotAsErrors>
     <DefineConstants>$(DefineConstants),LATEBINDING=True</DefineConstants>
-    <DefineConstants Condition="'$(TargetsWindows)' == 'true'">$(DefineConstants),TARGET_WINDOWS=True</DefineConstants>
     <NoWarn>$(NoWarn),CA1052,CA1810,CA2200</NoWarn>
-    <NoWarn Condition="'$(TargetsWindows)' != 'true'">$(NoWarn);CA1823</NoWarn>
     <!-- Avoid unused fields warnings in Unix build -->
     <AssemblyName>Microsoft.VisualBasic.Core</AssemblyName>
     <RemoveIntegerChecks>false</RemoveIntegerChecks>
     <RootNamespace />
     <TargetFrameworks>$(NetCoreAppCurrent);$(NetCoreAppCurrent)-windows</TargetFrameworks>
   </PropertyGroup>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <ILLinkDescriptorsXml Condition="'$(TargetsWindows)' == 'true'">$(MSBuildProjectDirectory)\ILLink\ILLink.Descriptors.Windows.xml</ILLinkDescriptorsXml>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <ILLinkDescriptorsXml Condition="'$(TargetPlatformIdentifier)' == 'windows'">$(MSBuildProjectDirectory)\ILLink\ILLink.Descriptors.Windows.xml</ILLinkDescriptorsXml>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'windows'">$(DefineConstants),TARGET_WINDOWS=True</DefineConstants>
+    <NoWarn Condition="'$(TargetPlatformIdentifier)' != 'windows'">$(NoWarn);CA1823</NoWarn>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="Microsoft\VisualBasic\Helpers\NativeMethods.vb" />
     <Compile Include="Microsoft\VisualBasic\Helpers\NativeTypes.vb" />
     <Compile Include="Microsoft\VisualBasic\Helpers\SafeNativeMethods.vb" />
diff --git a/src/libraries/Microsoft.Win32.Primitives/ref/Microsoft.Win32.Primitives.csproj b/src/libraries/Microsoft.Win32.Primitives/ref/Microsoft.Win32.Primitives.csproj
index 8a722c2adb533..553bc7bf128eb 100644
--- a/src/libraries/Microsoft.Win32.Primitives/ref/Microsoft.Win32.Primitives.csproj
+++ b/src/libraries/Microsoft.Win32.Primitives/ref/Microsoft.Win32.Primitives.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/Microsoft.Win32.Primitives/src/Microsoft.Win32.Primitives.csproj b/src/libraries/Microsoft.Win32.Primitives/src/Microsoft.Win32.Primitives.csproj
index 4f2d15aa3b6a5..a9c43608342de 100644
--- a/src/libraries/Microsoft.Win32.Primitives/src/Microsoft.Win32.Primitives.csproj
+++ b/src/libraries/Microsoft.Win32.Primitives/src/Microsoft.Win32.Primitives.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/Microsoft.Win32.Registry.AccessControl/src/Microsoft.Win32.Registry.AccessControl.csproj b/src/libraries/Microsoft.Win32.Registry.AccessControl/src/Microsoft.Win32.Registry.AccessControl.csproj
index 506507556b443..a86ab3b729f43 100644
--- a/src/libraries/Microsoft.Win32.Registry.AccessControl/src/Microsoft.Win32.Registry.AccessControl.csproj
+++ b/src/libraries/Microsoft.Win32.Registry.AccessControl/src/Microsoft.Win32.Registry.AccessControl.csproj
@@ -14,12 +14,12 @@ System.Security.AccessControl.RegistrySecurity</PackageDescription>
 
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) != '.NETFramework' and
-                                                            '$(TargetsWindows)' != 'true'">SR.PlatformNotSupported_RegistryAccessControl</GeneratePlatformNotSupportedAssemblyMessage>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
     <OmitResources Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETFramework'">true</OmitResources>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) != '.NETFramework' and '$(TargetPlatformIdentifier)' != 'windows'">SR.PlatformNotSupported_RegistryAccessControl</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
 
-  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework' or '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework' or '$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="Microsoft\Win32\RegistryAclExtensions.cs" />
   </ItemGroup>
 
diff --git a/src/libraries/Microsoft.Win32.Registry/ref/Microsoft.Win32.Registry.csproj b/src/libraries/Microsoft.Win32.Registry/ref/Microsoft.Win32.Registry.csproj
index 8d2c8aaa1e1b1..95230a12da938 100644
--- a/src/libraries/Microsoft.Win32.Registry/ref/Microsoft.Win32.Registry.csproj
+++ b/src/libraries/Microsoft.Win32.Registry/ref/Microsoft.Win32.Registry.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/Microsoft.Win32.Registry/src/Microsoft.Win32.Registry.csproj b/src/libraries/Microsoft.Win32.Registry/src/Microsoft.Win32.Registry.csproj
index d130810058032..82bd810903999 100644
--- a/src/libraries/Microsoft.Win32.Registry/src/Microsoft.Win32.Registry.csproj
+++ b/src/libraries/Microsoft.Win32.Registry/src/Microsoft.Win32.Registry.csproj
@@ -8,7 +8,9 @@
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <NoWarn Condition="'$(TargetsWindows)' != 'true'">$(NoWarn);CA1823</NoWarn> <!-- Avoid unused fields warnings in Unix build -->
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <!-- Avoid unused fields warnings in Unix build -->
+    <NoWarn Condition="'$(TargetPlatformIdentifier)' != 'windows'">$(NoWarn);CA1823</NoWarn>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="$(CommonPath)DisableRuntimeMarshalling.cs"
@@ -28,7 +30,7 @@
     <Compile Include="System\Security\AccessControl\RegistryRights.cs" />
     <Compile Include="System\Security\AccessControl\RegistrySecurity.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
              Link="Common\Interop\Windows\Interop.Libraries.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Errors.cs"
@@ -68,7 +70,7 @@
              Link="Microsoft\Win32\SafeHandles\SafeRegistryHandle.Windows.cs" />
     <Compile Include="System\Security\AccessControl\RegistrySecurity.Windows.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'windows'">
     <Compile Include="Microsoft\Win32\RegistryKey.FileSystem.cs" />
     <Compile Include="Microsoft\Win32\SafeHandles\SafeRegistryHandle.FileSystem.cs" />
     <Compile Include="System\Security\AccessControl\RegistrySecurity.FileSystem.cs" />
diff --git a/src/libraries/Microsoft.Win32.SystemEvents/src/Microsoft.Win32.SystemEvents.csproj b/src/libraries/Microsoft.Win32.SystemEvents/src/Microsoft.Win32.SystemEvents.csproj
index 86e6af7fdab5b..09adc148feb5f 100644
--- a/src/libraries/Microsoft.Win32.SystemEvents/src/Microsoft.Win32.SystemEvents.csproj
+++ b/src/libraries/Microsoft.Win32.SystemEvents/src/Microsoft.Win32.SystemEvents.csproj
@@ -12,13 +12,14 @@ Microsoft.Win32.SystemEvents</PackageDescription>
 
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
     <!-- Constrained Execution Regions only apply to netstandard2.0 and net4* -->
     <DefineConstants Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) != '.NETCoreApp'">$(DefineConstants);FEATURE_CER</DefineConstants>
     <IsPartialFacadeAssembly Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETFramework'">true</IsPartialFacadeAssembly>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetsWindows)' != 'true'">SR.PlatformNotSupported_SystemEvents</GeneratePlatformNotSupportedAssemblyMessage>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetPlatformIdentifier)' != 'windows'">SR.PlatformNotSupported_SystemEvents</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
 
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
              Link="Common\Interop\Windows\Interop.Libraries.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Errors.cs"
diff --git a/src/libraries/Microsoft.XmlSerializer.Generator/src/Microsoft.XmlSerializer.Generator.csproj b/src/libraries/Microsoft.XmlSerializer.Generator/src/Microsoft.XmlSerializer.Generator.csproj
index 93d874f618811..112de557fbc13 100644
--- a/src/libraries/Microsoft.XmlSerializer.Generator/src/Microsoft.XmlSerializer.Generator.csproj
+++ b/src/libraries/Microsoft.XmlSerializer.Generator/src/Microsoft.XmlSerializer.Generator.csproj
@@ -5,7 +5,7 @@
     <StringResourcesPath>..\..\System.Private.Xml\src\Resources\Strings.resx</StringResourcesPath>
     <StringResourcesName>FxResources.$(AssemblyName.Replace('-', '_')).SR</StringResourcesName>
     <OutputType>Exe</OutputType>
-    <TargetFrameworks>netstandard2.0</TargetFrameworks>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <EnableSingleFileAnalyzer>false</EnableSingleFileAnalyzer>
     <IsPackable>true</IsPackable>
     <PackageId>$(MSBuildProjectName)</PackageId>
diff --git a/src/libraries/System.AppContext/ref/System.AppContext.csproj b/src/libraries/System.AppContext/ref/System.AppContext.csproj
index 55b863d4d48ed..0d19d92c18f17 100644
--- a/src/libraries/System.AppContext/ref/System.AppContext.csproj
+++ b/src/libraries/System.AppContext/ref/System.AppContext.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.AppContext/src/System.AppContext.csproj b/src/libraries/System.AppContext/src/System.AppContext.csproj
index 4f2d15aa3b6a5..a9c43608342de 100644
--- a/src/libraries/System.AppContext/src/System.AppContext.csproj
+++ b/src/libraries/System.AppContext/src/System.AppContext.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Buffers/ref/System.Buffers.csproj b/src/libraries/System.Buffers/ref/System.Buffers.csproj
index 86924bfc712a3..7d42c1fc58bee 100644
--- a/src/libraries/System.Buffers/ref/System.Buffers.csproj
+++ b/src/libraries/System.Buffers/ref/System.Buffers.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Buffers/src/System.Buffers.csproj b/src/libraries/System.Buffers/src/System.Buffers.csproj
index 7e9aff4eedd4d..fe3825b1c1066 100644
--- a/src/libraries/System.Buffers/src/System.Buffers.csproj
+++ b/src/libraries/System.Buffers/src/System.Buffers.csproj
@@ -3,7 +3,7 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
     <ExcludeResourcesImport>true</ExcludeResourcesImport>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Collections.Concurrent/ref/System.Collections.Concurrent.csproj b/src/libraries/System.Collections.Concurrent/ref/System.Collections.Concurrent.csproj
index fb225b25b13d1..c54a6732d9803 100644
--- a/src/libraries/System.Collections.Concurrent/ref/System.Collections.Concurrent.csproj
+++ b/src/libraries/System.Collections.Concurrent/ref/System.Collections.Concurrent.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Collections.Concurrent/src/System.Collections.Concurrent.csproj b/src/libraries/System.Collections.Concurrent/src/System.Collections.Concurrent.csproj
index 0584d13dbe8e7..00088cbdd4e7e 100644
--- a/src/libraries/System.Collections.Concurrent/src/System.Collections.Concurrent.csproj
+++ b/src/libraries/System.Collections.Concurrent/src/System.Collections.Concurrent.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
     <Nullable>enable</Nullable>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System\ThrowHelper.cs" />
diff --git a/src/libraries/System.Collections.NonGeneric/ref/System.Collections.NonGeneric.csproj b/src/libraries/System.Collections.NonGeneric/ref/System.Collections.NonGeneric.csproj
index 84646e61be004..c73a0c807bf04 100644
--- a/src/libraries/System.Collections.NonGeneric/ref/System.Collections.NonGeneric.csproj
+++ b/src/libraries/System.Collections.NonGeneric/ref/System.Collections.NonGeneric.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <NoWarn>$(NoWarn);0618</NoWarn>
     <Nullable>enable</Nullable>
   </PropertyGroup>
diff --git a/src/libraries/System.Collections.NonGeneric/src/System.Collections.NonGeneric.csproj b/src/libraries/System.Collections.NonGeneric/src/System.Collections.NonGeneric.csproj
index 5009669653d11..95df0000154e3 100644
--- a/src/libraries/System.Collections.NonGeneric/src/System.Collections.NonGeneric.csproj
+++ b/src/libraries/System.Collections.NonGeneric/src/System.Collections.NonGeneric.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Collections.Specialized/ref/System.Collections.Specialized.csproj b/src/libraries/System.Collections.Specialized/ref/System.Collections.Specialized.csproj
index c4211d66d7aec..43b7e5d06dd69 100644
--- a/src/libraries/System.Collections.Specialized/ref/System.Collections.Specialized.csproj
+++ b/src/libraries/System.Collections.Specialized/ref/System.Collections.Specialized.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Collections.Specialized/src/System.Collections.Specialized.csproj b/src/libraries/System.Collections.Specialized/src/System.Collections.Specialized.csproj
index de6e924bef12a..5fef936424d71 100644
--- a/src/libraries/System.Collections.Specialized/src/System.Collections.Specialized.csproj
+++ b/src/libraries/System.Collections.Specialized/src/System.Collections.Specialized.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Collections/ref/System.Collections.csproj b/src/libraries/System.Collections/ref/System.Collections.csproj
index 9ab356c812196..92f76098f4e2a 100644
--- a/src/libraries/System.Collections/ref/System.Collections.csproj
+++ b/src/libraries/System.Collections/ref/System.Collections.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Collections/src/System.Collections.csproj b/src/libraries/System.Collections/src/System.Collections.csproj
index 28dd9816dc245..09c90780f7d25 100644
--- a/src/libraries/System.Collections/src/System.Collections.csproj
+++ b/src/libraries/System.Collections/src/System.Collections.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.ComponentModel.Annotations/ref/System.ComponentModel.Annotations.csproj b/src/libraries/System.ComponentModel.Annotations/ref/System.ComponentModel.Annotations.csproj
index 2267869cc4b98..88199b61fc5ee 100644
--- a/src/libraries/System.ComponentModel.Annotations/ref/System.ComponentModel.Annotations.csproj
+++ b/src/libraries/System.ComponentModel.Annotations/ref/System.ComponentModel.Annotations.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.ComponentModel.Annotations/src/System.ComponentModel.Annotations.csproj b/src/libraries/System.ComponentModel.Annotations/src/System.ComponentModel.Annotations.csproj
index 9c9dfebee9acc..7c62a82550e8d 100644
--- a/src/libraries/System.ComponentModel.Annotations/src/System.ComponentModel.Annotations.csproj
+++ b/src/libraries/System.ComponentModel.Annotations/src/System.ComponentModel.Annotations.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
     <!--
       Since many resource strings in this library are shown to an end-user,
diff --git a/src/libraries/System.ComponentModel.Composition/src/System.ComponentModel.Composition.csproj b/src/libraries/System.ComponentModel.Composition/src/System.ComponentModel.Composition.csproj
index 95b6da0e8e029..dc66b3e88c393 100644
--- a/src/libraries/System.ComponentModel.Composition/src/System.ComponentModel.Composition.csproj
+++ b/src/libraries/System.ComponentModel.Composition/src/System.ComponentModel.Composition.csproj
@@ -29,7 +29,7 @@ System.ComponentModel.Composition.ReflectionModel.ReflectionModelServices</Packa
   <PropertyGroup>
     <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetFramework)' == 'netstandard2.0'">SR.PlatformNotSupported_ComponentModel_Composition</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetFramework)' != 'netstandard2.0'">
+  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp'">
     <Compile Include="TypeForwards.cs" />
     <Compile Include="Microsoft\Internal\AttributeServices.cs" />
     <Compile Include="Microsoft\Internal\Collections\CollectionServices.cs" />
@@ -200,8 +200,6 @@ System.ComponentModel.Composition.ReflectionModel.ReflectionModelServices</Packa
              Link="Common\System\Composition\Diagnostics\DebuggerTraceWriter.cs" />
     <Compile Include="$(CommonPath)System\Composition\Diagnostics\TraceWriter.cs"
              Link="Common\System\Composition\Diagnostics\TraceWriter.cs" />
-    <Compile Include="$(CoreLibSharedDir)System\Diagnostics\CodeAnalysis\UnconditionalSuppressMessageAttribute.cs"
-             Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp'">
     <Reference Include="Microsoft.Win32.Primitives" />
diff --git a/src/libraries/System.ComponentModel.EventBasedAsync/ref/System.ComponentModel.EventBasedAsync.csproj b/src/libraries/System.ComponentModel.EventBasedAsync/ref/System.ComponentModel.EventBasedAsync.csproj
index 65a1807cd1c07..5a91c88354b1f 100644
--- a/src/libraries/System.ComponentModel.EventBasedAsync/ref/System.ComponentModel.EventBasedAsync.csproj
+++ b/src/libraries/System.ComponentModel.EventBasedAsync/ref/System.ComponentModel.EventBasedAsync.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.ComponentModel.EventBasedAsync/src/System.ComponentModel.EventBasedAsync.csproj b/src/libraries/System.ComponentModel.EventBasedAsync/src/System.ComponentModel.EventBasedAsync.csproj
index ad8ffe0f0061d..8b320923cab77 100644
--- a/src/libraries/System.ComponentModel.EventBasedAsync/src/System.ComponentModel.EventBasedAsync.csproj
+++ b/src/libraries/System.ComponentModel.EventBasedAsync/src/System.ComponentModel.EventBasedAsync.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.ComponentModel.Primitives/ref/System.ComponentModel.Primitives.csproj b/src/libraries/System.ComponentModel.Primitives/ref/System.ComponentModel.Primitives.csproj
index beda8b4a6df1a..89d0b6dddb710 100644
--- a/src/libraries/System.ComponentModel.Primitives/ref/System.ComponentModel.Primitives.csproj
+++ b/src/libraries/System.ComponentModel.Primitives/ref/System.ComponentModel.Primitives.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.ComponentModel.Primitives/src/System.ComponentModel.Primitives.csproj b/src/libraries/System.ComponentModel.Primitives/src/System.ComponentModel.Primitives.csproj
index 55db3244f4161..9de98f2f120e1 100644
--- a/src/libraries/System.ComponentModel.Primitives/src/System.ComponentModel.Primitives.csproj
+++ b/src/libraries/System.ComponentModel.Primitives/src/System.ComponentModel.Primitives.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <!--
       Since many resource strings in this library are shown to an end-user,
       always generate default resource string values which will be used when UseSystemResourceKeys is true in trimmed apps.
diff --git a/src/libraries/System.ComponentModel.TypeConverter/ref/System.ComponentModel.TypeConverter.csproj b/src/libraries/System.ComponentModel.TypeConverter/ref/System.ComponentModel.TypeConverter.csproj
index 10a6d2f9570b9..19e92d69408e9 100644
--- a/src/libraries/System.ComponentModel.TypeConverter/ref/System.ComponentModel.TypeConverter.csproj
+++ b/src/libraries/System.ComponentModel.TypeConverter/ref/System.ComponentModel.TypeConverter.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.ComponentModel.TypeConverter/src/System.ComponentModel.TypeConverter.csproj b/src/libraries/System.ComponentModel.TypeConverter/src/System.ComponentModel.TypeConverter.csproj
index db7c6d6c275cd..57e9c3e55cfe2 100644
--- a/src/libraries/System.ComponentModel.TypeConverter/src/System.ComponentModel.TypeConverter.csproj
+++ b/src/libraries/System.ComponentModel.TypeConverter/src/System.ComponentModel.TypeConverter.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.ComponentModel/ref/System.ComponentModel.csproj b/src/libraries/System.ComponentModel/ref/System.ComponentModel.csproj
index 43504ae8c4b73..663c10346c49d 100644
--- a/src/libraries/System.ComponentModel/ref/System.ComponentModel.csproj
+++ b/src/libraries/System.ComponentModel/ref/System.ComponentModel.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.ComponentModel/src/System.ComponentModel.csproj b/src/libraries/System.ComponentModel/src/System.ComponentModel.csproj
index 5b0195df044a1..a921f08302400 100644
--- a/src/libraries/System.ComponentModel/src/System.ComponentModel.csproj
+++ b/src/libraries/System.ComponentModel/src/System.ComponentModel.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Console/ref/System.Console.csproj b/src/libraries/System.Console/ref/System.Console.csproj
index 2394d7a594814..eeae6d27bb0c1 100644
--- a/src/libraries/System.Console/ref/System.Console.csproj
+++ b/src/libraries/System.Console/ref/System.Console.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Console/src/System.Console.csproj b/src/libraries/System.Console/src/System.Console.csproj
index db9d0fb39fb74..d76c64e0cc183 100644
--- a/src/libraries/System.Console/src/System.Console.csproj
+++ b/src/libraries/System.Console/src/System.Console.csproj
@@ -27,7 +27,7 @@
              Link="Common\System\Text\ConsoleEncoding.cs" />
   </ItemGroup>
   <!-- iOS/tvOS -->
-  <ItemGroup Condition="'$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'tvOS'">
     <Compile Include="System\ConsolePal.iOS.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.Log.cs"
              Link="Common\Interop\Unix\Interop.Log.cs" />
@@ -35,7 +35,7 @@
              Link="Common\Interop\Unix\Interop.Libraries.cs" />
   </ItemGroup>
   <!-- Android -->
-  <ItemGroup Condition="'$(TargetsAndroid)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Android'">
     <Compile Include="System\ConsolePal.Android.cs" />
     <Compile Include="$(CommonPath)Interop\Android\Interop.Logcat.cs">
       <Link>Common\Interop\Android\Interop.Logcat.cs</Link>
@@ -45,7 +45,7 @@
     </Compile>
   </ItemGroup>
   <!-- WebAssembly -->
-  <ItemGroup Condition="'$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="System\ConsolePal.WebAssembly.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.Dup.cs"
              Link="Common\Interop\Unix\Interop.Dup.cs" />
@@ -61,7 +61,7 @@
              Link="Common\Interop\Unix\Interop.IOErrors.cs" />
   </ItemGroup>
   <!-- Windows -->
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\ConsolePal.Windows.cs" />
     <Compile Include="$(CommonPath)System\Text\OSEncoding.Windows.cs"
              Link="Common\System\Text\OSEncoding.Windows.cs" />
@@ -155,7 +155,7 @@
              Link="Common\System\Text\ValueStringBuilder.cs" />
   </ItemGroup>
   <!-- Unix -->
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' and '$(TargetsAndroid)' != 'true' and '$(TargetsiOS)' != 'true' and '$(TargetstvOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Compile Include="System\ConsolePal.Unix.cs" />
     <Compile Include="System\TermInfo.cs" />
     <Compile Include="System\IO\StdInReader.cs" />
@@ -232,7 +232,7 @@
     <Reference Include="System.Threading" />
     <Reference Include="Microsoft.Win32.Primitives" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Browser'">
     <ProjectReference Include="$(LibrariesProjectRoot)System.Private.Runtime.InteropServices.JavaScript\src\System.Private.Runtime.InteropServices.JavaScript.csproj" />
   </ItemGroup>
 </Project>
diff --git a/src/libraries/System.Console/tests/System.Console.Tests.csproj b/src/libraries/System.Console/tests/System.Console.Tests.csproj
index 4418da53021a7..076efd2213a00 100644
--- a/src/libraries/System.Console/tests/System.Console.Tests.csproj
+++ b/src/libraries/System.Console/tests/System.Console.Tests.csproj
@@ -39,10 +39,10 @@
           Link="%(RecursiveDir)%(Filename)%(Extension)"
           CopyToOutputDirectory="PreserveNewest" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="ConsoleEncoding.Windows.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'windows'">
     <Compile Include="CancelKeyPress.Unix.cs" />
     <Compile Include="NonStandardConfiguration.Unix.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs"
diff --git a/src/libraries/System.Data.Common/ref/System.Data.Common.csproj b/src/libraries/System.Data.Common/ref/System.Data.Common.csproj
index ab75121dec942..b255e6f68e019 100644
--- a/src/libraries/System.Data.Common/ref/System.Data.Common.csproj
+++ b/src/libraries/System.Data.Common/ref/System.Data.Common.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <NoWarn>$(NoWarn);0618</NoWarn>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Data.Common/src/System.Data.Common.csproj b/src/libraries/System.Data.Common/src/System.Data.Common.csproj
index b836c7f2c8e14..a9ad614630fd3 100644
--- a/src/libraries/System.Data.Common/src/System.Data.Common.csproj
+++ b/src/libraries/System.Data.Common/src/System.Data.Common.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Data.DataSetExtensions/ref/System.Data.DataSetExtensions.csproj b/src/libraries/System.Data.DataSetExtensions/ref/System.Data.DataSetExtensions.csproj
index cedcb0aac6596..ae3518dee7cc7 100644
--- a/src/libraries/System.Data.DataSetExtensions/ref/System.Data.DataSetExtensions.csproj
+++ b/src/libraries/System.Data.DataSetExtensions/ref/System.Data.DataSetExtensions.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Data.DataSetExtensions/src/System.Data.DataSetExtensions.csproj b/src/libraries/System.Data.DataSetExtensions/src/System.Data.DataSetExtensions.csproj
index e5ff6a463dd77..bcb4ad6f1fb83 100644
--- a/src/libraries/System.Data.DataSetExtensions/src/System.Data.DataSetExtensions.csproj
+++ b/src/libraries/System.Data.DataSetExtensions/src/System.Data.DataSetExtensions.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
     <Nullable>enable</Nullable>
   </PropertyGroup>
diff --git a/src/libraries/System.Data.Odbc/src/System.Data.Odbc.csproj b/src/libraries/System.Data.Odbc/src/System.Data.Odbc.csproj
index d0818649229c5..de391f5ebf36d 100644
--- a/src/libraries/System.Data.Odbc/src/System.Data.Odbc.csproj
+++ b/src/libraries/System.Data.Odbc/src/System.Data.Odbc.csproj
@@ -20,15 +20,16 @@ System.Data.Odbc.OdbcTransaction</PackageDescription>
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
     <IsPartialFacadeAssembly Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETFramework'">true</IsPartialFacadeAssembly>
     <!-- https://github.com/dotnet/arcade/issues/5717 -->
     <NoWarn Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETCoreApp'">$(NoWarn);SA1121</NoWarn>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsAnyOS)' == 'true' and '$(IsPartialFacadeAssembly)' != 'true'">SR.Odbc_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetPlatformIdentifier)' == ''">SR.Odbc_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
   <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp'" >
     <Compile Include="System\Data\Odbc\ODBC32.Common.cs"/>
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp' and '$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="$(CommonPath)System\Data\Common\AdapterUtil.cs"
              Link="Common\System\Data\Common\AdapterUtil.cs" />
     <Compile Include="$(CommonPath)System\Data\Common\AdapterUtil.Drivers.cs"
@@ -132,15 +133,15 @@ System.Data.Odbc.OdbcTransaction</PackageDescription>
     <Compile Include="$(CommonPath)System\Runtime\InteropServices\HandleRefMarshaller.cs"
           Link="Common\System\Runtime\InteropServices\HandleRefMarshaller.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsLinux)' == 'true' or '$(TargetsFreeBSD)' == 'true' or '$(Targetsillumos)' == 'true' or '$(TargetsSolaris)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Linux' or '$(TargetPlatformIdentifier)' == 'FreeBSD' or '$(TargetPlatformIdentifier)' == 'illumos' or '$(TargetPlatformIdentifier)' == 'Solaris'">
     <Compile Include="$(CommonPath)Interop\Linux\Interop.Libraries.cs"
              Link="Common\Interop\Linux\Interop.Libraries.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsOSX)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'OSX' or '$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'tvOS'">
     <Compile Include="$(CommonPath)Interop\OSX\Interop.Libraries.cs"
              Link="Common\Interop\OSX\Interop.Libraries.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp' and '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
              Link="Common\Interop\Windows\Interop.Libraries.cs" />
   </ItemGroup>
diff --git a/src/libraries/System.Data.Odbc/tests/System.Data.Odbc.Tests.csproj b/src/libraries/System.Data.Odbc/tests/System.Data.Odbc.Tests.csproj
index 3ca325a2f883e..85a15ebe3d241 100644
--- a/src/libraries/System.Data.Odbc/tests/System.Data.Odbc.Tests.csproj
+++ b/src/libraries/System.Data.Odbc/tests/System.Data.Odbc.Tests.csproj
@@ -4,7 +4,8 @@
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <DefineConstants Condition="'$(TargetsWindows)' == 'true' or $([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETFramework'">$(DefineConstants);TargetsWindows</DefineConstants>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'windows' or $([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETFramework'">$(DefineConstants);TargetsWindows</DefineConstants>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="DependencyCheckTest.cs" />
@@ -18,28 +19,28 @@
     <Compile Include="TestCommon\CheckConnStrSetupFactAttribute.cs" />
     <Compile Include="OdbcParameterTests.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'windows' and '$(TargetFrameworkIdentifier)' != '.NETFramework'">
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs"
              Link="Common\Interop\Unix\Interop.Libraries.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsLinux)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Linux'">
     <Compile Include="$(CommonPath)Interop\Linux\Interop.Libraries.cs"
              Link="Common\Interop\Linux\Interop.Libraries.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsOSX)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'OSX' or '$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'tvOS'">
     <Compile Include="$(CommonPath)Interop\OSX\Interop.Libraries.cs"
              Link="Common\Interop\OSX\Interop.Libraries.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsFreeBSD)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'FreeBSD'">
     <Compile Include="$(CommonPath)Interop\FreeBSD\Interop.Libraries.cs"
              Link="Common\Interop\FreeBSD\Interop.Libraries.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true' or '$(TargetFrameworkIdentifier)' == '.NETFramework'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows' or '$(TargetFrameworkIdentifier)' == '.NETFramework'">
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
              Link="Common\Interop\Windows\Interop.Libraries.cs" />
     <Compile Include="ConnectionStrings.Windows.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' != 'true' and '$(TargetFrameworkIdentifier)' != '.NETFramework'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'windows' and '$(TargetFrameworkIdentifier)' != '.NETFramework'">
     <Compile Include="ConnectionStrings.Unix.cs" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp'">
diff --git a/src/libraries/System.Data.OleDb/src/System.Data.OleDb.csproj b/src/libraries/System.Data.OleDb/src/System.Data.OleDb.csproj
index ff91576165922..1f83a1ca2948d 100644
--- a/src/libraries/System.Data.OleDb/src/System.Data.OleDb.csproj
+++ b/src/libraries/System.Data.OleDb/src/System.Data.OleDb.csproj
@@ -26,12 +26,13 @@ System.Data.OleDb.OleDbTransaction</PackageDescription>
 
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
     <IsPartialFacadeAssembly Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETFramework'">true</IsPartialFacadeAssembly>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetsWindows)' != 'true'">SR.PlatformNotSupported_OleDb</GeneratePlatformNotSupportedAssemblyMessage>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetPlatformIdentifier)' != 'windows'">SR.PlatformNotSupported_OleDb</GeneratePlatformNotSupportedAssemblyMessage>
     <NoWarn Condition="'$(GeneratePlatformNotSupportedAssemblyMessage)' != ''">$(NoWarn);CS0618</NoWarn>
   </PropertyGroup>
 
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
              Link="Common\Interop\Windows\Interop.Libraries.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.GetUserDefaultLCID.cs"
@@ -129,13 +130,11 @@ System.Data.OleDb.OleDbTransaction</PackageDescription>
     <Compile Include="System\Data\ProviderBase\DbReferenceCollection.cs" />
     <Compile Include="System\Data\ProviderBase\WrappedIUnknown.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true' and '$(TargetFrameworkIdentifier)' == '.NETCoreApp'">
+
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="UnsafeNativeMethods.COMWrappers.cs" />
     <Compile Include="OleDbComWrappers.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetsWindows)' == 'true' and !$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net5.0'))">
-    <Compile Include="UnsafeNativeMethods.NoCOMWrappers.cs" />
-  </ItemGroup>
 
   <ItemGroup>
     <EmbeddedResource Include="Resources\System.Data.OleDb.OleDbMetaData.xml"
diff --git a/src/libraries/System.Diagnostics.Contracts/ref/System.Diagnostics.Contracts.csproj b/src/libraries/System.Diagnostics.Contracts/ref/System.Diagnostics.Contracts.csproj
index 193726ce1e00d..66fd17f7438b4 100644
--- a/src/libraries/System.Diagnostics.Contracts/ref/System.Diagnostics.Contracts.csproj
+++ b/src/libraries/System.Diagnostics.Contracts/ref/System.Diagnostics.Contracts.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Diagnostics.Contracts/src/System.Diagnostics.Contracts.csproj b/src/libraries/System.Diagnostics.Contracts/src/System.Diagnostics.Contracts.csproj
index dd3dc2940a54b..5ecfe239de6f7 100644
--- a/src/libraries/System.Diagnostics.Contracts/src/System.Diagnostics.Contracts.csproj
+++ b/src/libraries/System.Diagnostics.Contracts/src/System.Diagnostics.Contracts.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Diagnostics.Debug/ref/System.Diagnostics.Debug.csproj b/src/libraries/System.Diagnostics.Debug/ref/System.Diagnostics.Debug.csproj
index 1d1a2b817e977..7ae0399d1ab0c 100644
--- a/src/libraries/System.Diagnostics.Debug/ref/System.Diagnostics.Debug.csproj
+++ b/src/libraries/System.Diagnostics.Debug/ref/System.Diagnostics.Debug.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Diagnostics.Debug/src/System.Diagnostics.Debug.csproj b/src/libraries/System.Diagnostics.Debug/src/System.Diagnostics.Debug.csproj
index dd3dc2940a54b..5ecfe239de6f7 100644
--- a/src/libraries/System.Diagnostics.Debug/src/System.Diagnostics.Debug.csproj
+++ b/src/libraries/System.Diagnostics.Debug/src/System.Diagnostics.Debug.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Diagnostics.DiagnosticSource/tests/System.Diagnostics.DiagnosticSource.Tests.csproj b/src/libraries/System.Diagnostics.DiagnosticSource/tests/System.Diagnostics.DiagnosticSource.Tests.csproj
index a9191d5aa8289..e57e7a1ccec14 100644
--- a/src/libraries/System.Diagnostics.DiagnosticSource/tests/System.Diagnostics.DiagnosticSource.Tests.csproj
+++ b/src/libraries/System.Diagnostics.DiagnosticSource/tests/System.Diagnostics.DiagnosticSource.Tests.csproj
@@ -6,7 +6,7 @@
   <PropertyGroup>
     <DefineConstants Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETCoreApp'">$(DefineConstants);MEMORYMARSHAL_SUPPORT</DefineConstants>
   </PropertyGroup>
-  <ItemGroup Condition="!$(TargetFramework.StartsWith('net4'))">
+  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp'">
     <Compile Include="DiagnosticSourceEventSourceBridgeTests.cs" />
   </ItemGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Diagnostics.EventLog/src/Messages/System.Diagnostics.EventLog.Messages.csproj b/src/libraries/System.Diagnostics.EventLog/src/Messages/System.Diagnostics.EventLog.Messages.csproj
index d2ad06b758f4a..56a71b1d27b68 100644
--- a/src/libraries/System.Diagnostics.EventLog/src/Messages/System.Diagnostics.EventLog.Messages.csproj
+++ b/src/libraries/System.Diagnostics.EventLog/src/Messages/System.Diagnostics.EventLog.Messages.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0</TargetFrameworks>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <Win32Resource>EventLogMessages.res</Win32Resource>
     <!-- Override the parent Directory.Build.props -->
     <SupportedOSPlatforms />
diff --git a/src/libraries/System.Diagnostics.EventLog/src/System.Diagnostics.EventLog.csproj b/src/libraries/System.Diagnostics.EventLog/src/System.Diagnostics.EventLog.csproj
index fd558833ee2df..a97fd6227e0cd 100644
--- a/src/libraries/System.Diagnostics.EventLog/src/System.Diagnostics.EventLog.csproj
+++ b/src/libraries/System.Diagnostics.EventLog/src/System.Diagnostics.EventLog.csproj
@@ -17,11 +17,12 @@ System.Diagnostics.EventLog</PackageDescription>
 
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
     <IsPartialFacadeAssembly Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETFramework'">true</IsPartialFacadeAssembly>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetsWindows)' != 'true'">SR.PlatformNotSupported_EventLog</GeneratePlatformNotSupportedAssemblyMessage>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetPlatformIdentifier)' != 'windows'">SR.PlatformNotSupported_EventLog</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
 
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\Diagnostics\EntryWrittenEventArgs.cs" />
     <Compile Include="System\Diagnostics\EntryWrittenEventHandler.cs" />
     <Compile Include="System\Diagnostics\EventData.cs" />
@@ -151,7 +152,7 @@ System.Diagnostics.EventLog</PackageDescription>
     <PackageReference Include="System.Security.Principal.Windows" Version="$(SystemSecurityPrincipalWindowsVersion)" />
   </ItemGroup>
 
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <ProjectReference Include="Messages\System.Diagnostics.EventLog.Messages.csproj"
                       ReferenceOutputAssembly="false"
                       OutputItemType="TfmRuntimeSpecificPackageFile"
diff --git a/src/libraries/System.Diagnostics.FileVersionInfo/ref/System.Diagnostics.FileVersionInfo.csproj b/src/libraries/System.Diagnostics.FileVersionInfo/ref/System.Diagnostics.FileVersionInfo.csproj
index 85460a8410d6d..eb11026ebbbc7 100644
--- a/src/libraries/System.Diagnostics.FileVersionInfo/ref/System.Diagnostics.FileVersionInfo.csproj
+++ b/src/libraries/System.Diagnostics.FileVersionInfo/ref/System.Diagnostics.FileVersionInfo.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Diagnostics.FileVersionInfo/src/System.Diagnostics.FileVersionInfo.csproj b/src/libraries/System.Diagnostics.FileVersionInfo/src/System.Diagnostics.FileVersionInfo.csproj
index fae2dee239225..3bc748311c5f6 100644
--- a/src/libraries/System.Diagnostics.FileVersionInfo/src/System.Diagnostics.FileVersionInfo.csproj
+++ b/src/libraries/System.Diagnostics.FileVersionInfo/src/System.Diagnostics.FileVersionInfo.csproj
@@ -6,14 +6,15 @@
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsAnyOS)' == 'true'">SR.DiagnosticsFileVersionInfo_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == ''">SR.DiagnosticsFileVersionInfo_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage> 
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="System\Diagnostics\FileVersionInfo.cs" />
     <Compile Include="$(CommonPath)DisableRuntimeMarshalling.cs"
              Link="Common\DisableRuntimeMarshalling.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\Diagnostics\FileVersionInfo.Windows.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
              Link="Common\Interop\Windows\Interop.Libraries.cs" />
@@ -32,7 +33,7 @@
     <Compile Include="$(CommonPath)Interop\Windows\Version\Interop.VSFixedFileInfo.cs"
              Link="Common\Interop\Windows\Interop.VSFixedFileInfo.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Compile Include="System\Diagnostics\FileVersionInfo.Unix.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs"
              Link="Common\Interop\Unix\Interop.Libraries.cs" />
@@ -49,7 +50,7 @@
     <Reference Include="System.Runtime.Extensions" />
     <Reference Include="System.Runtime.InteropServices" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Reference Include="System.Collections.Immutable" />
     <Reference Include="System.Reflection.Metadata" />
   </ItemGroup>
diff --git a/src/libraries/System.Diagnostics.FileVersionInfo/tests/System.Diagnostics.FileVersionInfo.Tests/System.Diagnostics.FileVersionInfo.Tests.csproj b/src/libraries/System.Diagnostics.FileVersionInfo/tests/System.Diagnostics.FileVersionInfo.Tests/System.Diagnostics.FileVersionInfo.Tests.csproj
index 9b99ef0ab8124..36f5ea370f995 100644
--- a/src/libraries/System.Diagnostics.FileVersionInfo/tests/System.Diagnostics.FileVersionInfo.Tests/System.Diagnostics.FileVersionInfo.Tests.csproj
+++ b/src/libraries/System.Diagnostics.FileVersionInfo/tests/System.Diagnostics.FileVersionInfo.Tests/System.Diagnostics.FileVersionInfo.Tests.csproj
@@ -29,14 +29,14 @@
     <Compile Include="FileVersionInfoTest.cs" />
     <Compile Include="AssemblyInfo.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="FileVersionInfoTest.Windows.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
              Link="ProductionCode\Common\Interop\Windows\Interop.Libraries.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.VerLanguageName.cs"
              Link="ProductionCode\Common\Interop\Windows\Kernel32\Interop.VerLanguageName.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="FileVersionInfoTest.Unix.cs" />
   </ItemGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Diagnostics.PerformanceCounter/src/System.Diagnostics.PerformanceCounter.csproj b/src/libraries/System.Diagnostics.PerformanceCounter/src/System.Diagnostics.PerformanceCounter.csproj
index f90314643f412..ff0ebc6c35834 100644
--- a/src/libraries/System.Diagnostics.PerformanceCounter/src/System.Diagnostics.PerformanceCounter.csproj
+++ b/src/libraries/System.Diagnostics.PerformanceCounter/src/System.Diagnostics.PerformanceCounter.csproj
@@ -3,7 +3,6 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent);$(NetCoreAppMinimum)-windows;$(NetCoreAppMinimum);netstandard2.0;$(NetFrameworkMinimum)</TargetFrameworks>
     <NoWarn>$(NoWarn);CA1847</NoWarn>
-    <NoWarn Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'">$(NoWarn);CA1066</NoWarn>
     <Nullable>annotations</Nullable>
     <IsPackable>true</IsPackable>
     <PackageDescription>Provides the System.Diagnostics.PerformanceCounter class, which allows access to Windows performance counters.
@@ -13,10 +12,12 @@ System.Diagnostics.PerformanceCounter</PackageDescription>
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <NoWarn Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) != '.NETCoreApp'">$(NoWarn);CA1066</NoWarn>
     <IsPartialFacadeAssembly Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETFramework'">true</IsPartialFacadeAssembly>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetsWindows)' != 'true'">SR.PlatformNotSupported_PerfCounters</GeneratePlatformNotSupportedAssemblyMessage>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetPlatformIdentifier)' != 'windows'">SR.PlatformNotSupported_PerfCounters</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\Diagnostics\DiagnosticsConfiguration.cs" />
     <Compile Include="System\Diagnostics\CounterCreationData.cs" />
     <Compile Include="System\Diagnostics\CounterCreationDataCollection.cs" />
diff --git a/src/libraries/System.Diagnostics.Process/ref/System.Diagnostics.Process.csproj b/src/libraries/System.Diagnostics.Process/ref/System.Diagnostics.Process.csproj
index e30075373d547..2f392d43da189 100644
--- a/src/libraries/System.Diagnostics.Process/ref/System.Diagnostics.Process.csproj
+++ b/src/libraries/System.Diagnostics.Process/ref/System.Diagnostics.Process.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Diagnostics.Process/src/System.Diagnostics.Process.csproj b/src/libraries/System.Diagnostics.Process/src/System.Diagnostics.Process.csproj
index 8a41187ffa5cb..c91e7c693aad7 100644
--- a/src/libraries/System.Diagnostics.Process/src/System.Diagnostics.Process.csproj
+++ b/src/libraries/System.Diagnostics.Process/src/System.Diagnostics.Process.csproj
@@ -2,17 +2,16 @@
   <PropertyGroup>
     <DefineConstants>$(DefineConstants);FEATURE_REGISTRY</DefineConstants>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-FreeBSD;$(NetCoreAppCurrent)-Linux;$(NetCoreAppCurrent);$(NetCoreAppCurrent)-OSX;$(NetCoreAppCurrent)-MacCatalyst;$(NetCoreAppCurrent)-iOS;$(NetCoreAppCurrent)-tvOS</TargetFrameworks>
+    <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-FreeBSD;$(NetCoreAppCurrent)-Linux;$(NetCoreAppCurrent)-OSX;$(NetCoreAppCurrent)-MacCatalyst;$(NetCoreAppCurrent)-iOS;$(NetCoreAppCurrent)-tvOS;$(NetCoreAppCurrent)</TargetFrameworks>
     <Nullable>enable</Nullable>
-    <!-- Suppress unused field warnings when using PlatformNotSupportedException stubs -->
   </PropertyGroup>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsAnyOS)' == 'true'">SR.Process_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == ''">SR.Process_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <IsiOSLike Condition="'$(TargetPlatformIdentifier)' == 'MacCatalyst' or '$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'tvOS'">true</IsiOSLike>
   </PropertyGroup>
-  <PropertyGroup>
-    <IsiOSLike Condition="'$(TargetsMacCatalyst)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true'">true</IsiOSLike>
-  </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="Microsoft\Win32\SafeHandles\SafeProcessHandle.cs" />
     <Compile Include="System\Collections\Specialized\DictionaryWrapper.cs" />
     <Compile Include="System\Diagnostics\AsyncStreamReader.cs" />
@@ -44,7 +43,7 @@
     <Compile Include="$(CommonPath)System\Text\ValueStringBuilder.cs"
              Link="Common\System\Text\ValueStringBuilder.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.EnumProcessModules.cs"
              Link="Common\Interop\Windows\Kernel32\Interop.EnumProcessModules.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.FormatMessage.cs"
@@ -77,8 +76,6 @@
              Link="Common\Interop\Windows\User32\Interop.SendMessageTimeout.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\User32\Interop.WaitForInputIdle.cs"
              Link="Common\Interop\Windows\User32\Interop.WaitForInputIdle.cs" />
-  </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsWindows)' == 'true'">
     <Compile Include="$(CommonPath)Microsoft\Win32\SafeHandles\SafeTokenHandle.cs"
              Link="Microsoft\Win32\SafeHandles\SafeTokenHandle.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
@@ -148,7 +145,7 @@
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.SetPriorityClass.cs"
              Link="Common\Interop\Windows\Kernel32\Interop.SetPriorityClass.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.DuplicateHandle_SafeFileHandle.cs"
-         Link="Common\Interop\Windows\kernel32\Interop.DuplicateHandle_SafeFileHandle.cs" />
+             Link="Common\Interop\Windows\kernel32\Interop.DuplicateHandle_SafeFileHandle.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.DuplicateHandle_SafeWaitHandle.cs"
              Link="Common\Interop\Windows\kernel32\Interop.DuplicateHandle_SafeWaitHandle.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.ProcessWaitHandle.cs"
@@ -222,7 +219,7 @@
     <Compile Include="System\Diagnostics\ProcessThread.Windows.cs" />
     <Compile Include="System\Diagnostics\ProcessThreadTimes.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows'">
     <Compile Include="Microsoft\Win32\SafeHandles\SafeProcessHandle.Unix.cs" />
     <Compile Include="System\Diagnostics\Process.Unix.cs" />
     <Compile Include="System\Diagnostics\ProcessManager.Unix.cs" />
@@ -285,15 +282,15 @@
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.IsMemberOfGroup.cs"
              Link="Common\Interop\Unix\Interop.IsMemberOfGroup.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsUnix)' == 'true' and '$(IsiOSLike)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows' and '$(IsiOSLike)' != 'true'">
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.ConfigureTerminalForChildProcess.cs"
              Link="Common\Interop\Unix\Interop.ConfigureTerminalForChildProcess.cs" />
     <Compile Include="System\Diagnostics\Process.ConfigureTerminalForChildProcesses.Unix.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsUnix)' == 'true' and '$(IsiOSLike)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows' and '$(IsiOSLike)' == 'true'">
     <Compile Include="System\Diagnostics\Process.ConfigureTerminalForChildProcesses.iOS.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsLinux)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Linux'">
     <Compile Include="System\Diagnostics\Process.Linux.cs" />
     <Compile Include="System\Diagnostics\ProcessManager.Linux.cs" />
     <Compile Include="System\Diagnostics\ProcessThread.Linux.cs" />
@@ -308,7 +305,7 @@
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.SchedGetSetAffinity.cs"
              Link="Common\Interop\Linux\Interop.SchedGetSetAffinity.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsOSX)' == 'true' or '$(TargetsMacCatalyst)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'OSX' or '$(TargetPlatformIdentifier)' == 'MacCatalyst'">
     <Compile Include="System\Diagnostics\Process.BSD.cs" />
     <Compile Include="System\Diagnostics\Process.OSX.cs" />
     <Compile Include="System\Diagnostics\ProcessManager.BSD.cs" />
@@ -321,17 +318,17 @@
     <Compile Include="$(CommonPath)Interop\OSX\Interop.Libraries.cs"
              Link="Common\Interop\OSX\Interop.Libraries.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)Interop\Windows\Shell32\Interop.ShellExecuteExW.cs"
              Link="Common\Interop\Windows\Shell32\Interop.ShellExecuteExW.cs" />
     <Compile Include="System\Diagnostics\Process.Win32.cs" />
     <Compile Include="System\Diagnostics\ProcessManager.Win32.cs" />
     <Compile Include="System\Diagnostics\ProcessStartInfo.Win32.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true' and '$(TargetsiOS)' != 'true' and '$(TargetstvOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'iOS' and '$(TargetPlatformIdentifier)' != 'tvOS'">
     <Compile Include="System\Diagnostics\Process.NonUap.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsFreeBSD)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'FreeBSD'">
     <Compile Include="System\Diagnostics\Process.BSD.cs" />
     <Compile Include="System\Diagnostics\Process.FreeBSD.cs" />
     <Compile Include="System\Diagnostics\ProcessManager.BSD.cs" />
@@ -344,12 +341,12 @@
     <Compile Include="$(CommonPath)Interop\FreeBSD\Interop.Process.GetProcInfo.cs"
              Link="Common\Interop\FreeBSD\Interop.Process.GetProcInfo.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'tvOS'">
     <Compile Include="System\Diagnostics\Process.iOS.cs" />
     <Compile Include="System\Diagnostics\ProcessManager.iOS.cs" />
     <Compile Include="System\Diagnostics\ProcessThread.iOS.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnknownUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'UnknownUnix'">
     <Compile Include="System\Diagnostics\Process.UnknownUnix.cs" />
     <Compile Include="System\Diagnostics\ProcessManager.UnknownUnix.cs" />
     <Compile Include="System\Diagnostics\ProcessThread.UnknownUnix.cs" />
diff --git a/src/libraries/System.Diagnostics.Process/tests/System.Diagnostics.Process.Tests.csproj b/src/libraries/System.Diagnostics.Process/tests/System.Diagnostics.Process.Tests.csproj
index 783e4ad21e9c7..089d4fdeb4dcf 100644
--- a/src/libraries/System.Diagnostics.Process/tests/System.Diagnostics.Process.Tests.csproj
+++ b/src/libraries/System.Diagnostics.Process/tests/System.Diagnostics.Process.Tests.csproj
@@ -1,12 +1,16 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <DefineConstants Condition="'$(TargetsWindows)' == 'true'">$(DefineConstants);TargetsWindows</DefineConstants>
     <IncludeRemoteExecutor>true</IncludeRemoteExecutor>
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent)-Browser</TargetFrameworks>
     <IgnoreForCI Condition="'$(TargetOS)' == 'Browser'">true</IgnoreForCI>
     <EnableDllImportGenerator>true</EnableDllImportGenerator>
   </PropertyGroup>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
+  <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'windows'">$(DefineConstants);TargetsWindows</DefineConstants>
+  </PropertyGroup>
   <ItemGroup>
     <Compile Include="$(CoreLibSharedDir)System\PasteArguments.cs"
              Link="System\PasteArguments.cs" />
@@ -37,7 +41,7 @@
     <Compile Include="RemotelyInvokable.cs" />
     <Compile Include="AssemblyInfo.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="ProcessModuleTests.Windows.cs" />
     <Compile Include="ProcessTests.Windows.cs" />
     <Compile Include="ProcessThreadTests.Windows.cs" />
@@ -50,7 +54,7 @@
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.FreeLibrary.cs"
              Link="Common\Interop\Windows\Kernel32\Interop.FreeLibrary.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="Interop.Unix.cs" />
     <Compile Include="ProcessTests.Unix.cs" />
     <Compile Include="ProcessThreadTests.Unix.cs" />
diff --git a/src/libraries/System.Diagnostics.StackTrace/ref/System.Diagnostics.StackTrace.csproj b/src/libraries/System.Diagnostics.StackTrace/ref/System.Diagnostics.StackTrace.csproj
index 35e82eee5e77b..ed8643bdf44e3 100644
--- a/src/libraries/System.Diagnostics.StackTrace/ref/System.Diagnostics.StackTrace.csproj
+++ b/src/libraries/System.Diagnostics.StackTrace/ref/System.Diagnostics.StackTrace.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Diagnostics.StackTrace/src/System.Diagnostics.StackTrace.csproj b/src/libraries/System.Diagnostics.StackTrace/src/System.Diagnostics.StackTrace.csproj
index 8cecf8e2327cd..7962381d9d74b 100644
--- a/src/libraries/System.Diagnostics.StackTrace/src/System.Diagnostics.StackTrace.csproj
+++ b/src/libraries/System.Diagnostics.StackTrace/src/System.Diagnostics.StackTrace.csproj
@@ -3,7 +3,7 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
     <Nullable>enable</Nullable>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System\Diagnostics\StackTraceSymbols.cs" />
diff --git a/src/libraries/System.Diagnostics.TextWriterTraceListener/ref/System.Diagnostics.TextWriterTraceListener.csproj b/src/libraries/System.Diagnostics.TextWriterTraceListener/ref/System.Diagnostics.TextWriterTraceListener.csproj
index d83d56c13eb41..7238adfa34574 100644
--- a/src/libraries/System.Diagnostics.TextWriterTraceListener/ref/System.Diagnostics.TextWriterTraceListener.csproj
+++ b/src/libraries/System.Diagnostics.TextWriterTraceListener/ref/System.Diagnostics.TextWriterTraceListener.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Diagnostics.TextWriterTraceListener/src/System.Diagnostics.TextWriterTraceListener.csproj b/src/libraries/System.Diagnostics.TextWriterTraceListener/src/System.Diagnostics.TextWriterTraceListener.csproj
index d179081ce20e3..cf755b59130cf 100644
--- a/src/libraries/System.Diagnostics.TextWriterTraceListener/src/System.Diagnostics.TextWriterTraceListener.csproj
+++ b/src/libraries/System.Diagnostics.TextWriterTraceListener/src/System.Diagnostics.TextWriterTraceListener.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Diagnostics.Tools/ref/System.Diagnostics.Tools.csproj b/src/libraries/System.Diagnostics.Tools/ref/System.Diagnostics.Tools.csproj
index d1f6b1fa85868..81fa1ed3e681d 100644
--- a/src/libraries/System.Diagnostics.Tools/ref/System.Diagnostics.Tools.csproj
+++ b/src/libraries/System.Diagnostics.Tools/ref/System.Diagnostics.Tools.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Diagnostics.Tools/src/System.Diagnostics.Tools.csproj b/src/libraries/System.Diagnostics.Tools/src/System.Diagnostics.Tools.csproj
index 4f2d15aa3b6a5..a9c43608342de 100644
--- a/src/libraries/System.Diagnostics.Tools/src/System.Diagnostics.Tools.csproj
+++ b/src/libraries/System.Diagnostics.Tools/src/System.Diagnostics.Tools.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Diagnostics.TraceSource/ref/System.Diagnostics.TraceSource.csproj b/src/libraries/System.Diagnostics.TraceSource/ref/System.Diagnostics.TraceSource.csproj
index a344553052ce6..093d289611fad 100644
--- a/src/libraries/System.Diagnostics.TraceSource/ref/System.Diagnostics.TraceSource.csproj
+++ b/src/libraries/System.Diagnostics.TraceSource/ref/System.Diagnostics.TraceSource.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Diagnostics.TraceSource/src/System.Diagnostics.TraceSource.csproj b/src/libraries/System.Diagnostics.TraceSource/src/System.Diagnostics.TraceSource.csproj
index 7b62f85f073ba..2910efd27197f 100644
--- a/src/libraries/System.Diagnostics.TraceSource/src/System.Diagnostics.TraceSource.csproj
+++ b/src/libraries/System.Diagnostics.TraceSource/src/System.Diagnostics.TraceSource.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <DefineConstants>$(DefineConstants);TRACE</DefineConstants>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Diagnostics.Tracing/ref/System.Diagnostics.Tracing.csproj b/src/libraries/System.Diagnostics.Tracing/ref/System.Diagnostics.Tracing.csproj
index 4a57f065745ff..b59d58aabfd2d 100644
--- a/src/libraries/System.Diagnostics.Tracing/ref/System.Diagnostics.Tracing.csproj
+++ b/src/libraries/System.Diagnostics.Tracing/ref/System.Diagnostics.Tracing.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Diagnostics.Tracing/src/System.Diagnostics.Tracing.csproj b/src/libraries/System.Diagnostics.Tracing/src/System.Diagnostics.Tracing.csproj
index dd3dc2940a54b..5ecfe239de6f7 100644
--- a/src/libraries/System.Diagnostics.Tracing/src/System.Diagnostics.Tracing.csproj
+++ b/src/libraries/System.Diagnostics.Tracing/src/System.Diagnostics.Tracing.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Diagnostics.Tracing/tests/System.Diagnostics.Tracing.Tests.csproj b/src/libraries/System.Diagnostics.Tracing/tests/System.Diagnostics.Tracing.Tests.csproj
index 66eb092dee110..c8f85a372ea7c 100644
--- a/src/libraries/System.Diagnostics.Tracing/tests/System.Diagnostics.Tracing.Tests.csproj
+++ b/src/libraries/System.Diagnostics.Tracing/tests/System.Diagnostics.Tracing.Tests.csproj
@@ -6,7 +6,7 @@
     <IncludeRemoteExecutor>true</IncludeRemoteExecutor>
   </PropertyGroup>
   <!-- Windows only files -->
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="BasicEventSourceTest\Harness\EtwListener.cs" />
     <Compile Include="BasicEventSourceTest\TestEventCounter.Etw.cs" />
     <Compile Include="BasicEventSourceTest\TestsWrite.Etw.cs" />
diff --git a/src/libraries/System.DirectoryServices.AccountManagement/src/System.DirectoryServices.AccountManagement.csproj b/src/libraries/System.DirectoryServices.AccountManagement/src/System.DirectoryServices.AccountManagement.csproj
index b518e6ecd1f3d..8c92ed4fc9ed8 100644
--- a/src/libraries/System.DirectoryServices.AccountManagement/src/System.DirectoryServices.AccountManagement.csproj
+++ b/src/libraries/System.DirectoryServices.AccountManagement/src/System.DirectoryServices.AccountManagement.csproj
@@ -16,9 +16,10 @@
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsWindows)' != 'true'">SR.DirectoryServicesAccountManagement_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' != 'windows'">SR.DirectoryServicesAccountManagement_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\DirectoryServices\AccountManagement\interopt.cs" />
     <Compile Include="System\DirectoryServices\AccountManagement\PrincipalSearcher.cs" />
     <Compile Include="System\DirectoryServices\AccountManagement\Utils.cs" />
@@ -224,7 +225,7 @@
   <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0'))">
     <Reference Include="System.Security.Cryptography" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'">
+  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETStandard'">
     <PackageReference Include="System.Security.Principal.Windows" Version="$(SystemSecurityPrincipalWindowsVersion)" />
   </ItemGroup>
 </Project>
diff --git a/src/libraries/System.DirectoryServices.Protocols/src/System.DirectoryServices.Protocols.csproj b/src/libraries/System.DirectoryServices.Protocols/src/System.DirectoryServices.Protocols.csproj
index 366ab1b31854d..43c120b0a74a0 100644
--- a/src/libraries/System.DirectoryServices.Protocols/src/System.DirectoryServices.Protocols.csproj
+++ b/src/libraries/System.DirectoryServices.Protocols/src/System.DirectoryServices.Protocols.csproj
@@ -13,9 +13,10 @@
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsAnyOS)' == 'true'">SR.DirectoryServicesProtocols_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == ''">SR.DirectoryServicesProtocols_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="System\DirectoryServices\Protocols\common\AuthTypes.cs" />
     <Compile Include="System\DirectoryServices\Protocols\common\BerConverter.cs" />
     <Compile Include="System\DirectoryServices\Protocols\common\DereferenceAlias.cs" />
@@ -52,7 +53,7 @@
       <Link>Common\Interop\Windows\Interop.BOOL.cs</Link>
     </Compile>
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\DirectoryServices\Protocols\common\BerConverter.Windows.cs" />
     <Compile Include="System\DirectoryServices\Protocols\common\QuotaControl.Windows.cs" />
     <Compile Include="System\DirectoryServices\Protocols\Interop\LdapPal.Windows.cs" />
@@ -70,7 +71,7 @@
       <Link>Common\Interop\Windows\Wldap32\Interop.Ber.cs</Link>
     </Compile>
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Linux' or '$(TargetPlatformIdentifier)' == 'OSX'">
     <Compile Include="System\DirectoryServices\Protocols\common\BerConverter.Linux.cs" />
     <Compile Include="System\DirectoryServices\Protocols\common\QuotaControl.Linux.cs" />
     <Compile Include="System\DirectoryServices\Protocols\Interop\LdapPal.Linux.cs" />
@@ -89,12 +90,12 @@
       <Link>Common\Interop\Linux\OpenLdap\Interop.Ber.cs</Link>
     </Compile>
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsLinux)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Linux'">
     <Compile Include="$(CommonPath)Interop\Linux\Interop.Libraries.cs">
       <Link>Common\Interop\Linux\Interop.Libraries.cs</Link>
     </Compile>
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsOSX)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'OSX'">
     <Compile Include="$(CommonPath)Interop\OSX\Interop.Libraries.cs">
       <Link>Common\Interop\OSX\Interop.Libraries.cs</Link>
     </Compile>
@@ -124,7 +125,7 @@
   <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0'))">
     <Reference Include="System.Security.Cryptography" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'">
+  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETStandard'">
     <PackageReference Include="System.Security.Principal.Windows" Version="$(SystemSecurityPrincipalWindowsVersion)" />
   </ItemGroup>
 </Project>
diff --git a/src/libraries/System.DirectoryServices/src/System.DirectoryServices.csproj b/src/libraries/System.DirectoryServices/src/System.DirectoryServices.csproj
index 9f4bbc7733bed..409bae7e786ba 100644
--- a/src/libraries/System.DirectoryServices/src/System.DirectoryServices.csproj
+++ b/src/libraries/System.DirectoryServices/src/System.DirectoryServices.csproj
@@ -25,9 +25,10 @@ System.DirectoryServices.ActiveDirectory.DomainController</PackageDescription>
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsWindows)' != 'true'">SR.DirectoryServices_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' != 'windows'">SR.DirectoryServices_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\DirectoryServices\ActiveDirectorySecurity.cs" />
     <Compile Include="System\DirectoryServices\AdsVLV.cs" />
     <Compile Include="System\DirectoryServices\AuthenticationTypes.cs" />
@@ -273,7 +274,7 @@ System.DirectoryServices.ActiveDirectory.DomainController</PackageDescription>
   <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0'))">
     <Reference Include="System.Security.Cryptography" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'">
+  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETStandard'">
     <PackageReference Include="System.IO.FileSystem.AccessControl" Version="$(SystemIOFileSystemAccessControlVersion)" />
     <PackageReference Include="System.Security.AccessControl" Version="$(SystemSecurityAccessControlVersion)" />
     <PackageReference Include="System.Security.Principal.Windows" Version="$(SystemSecurityPrincipalWindowsVersion)" />
diff --git a/src/libraries/System.DirectoryServices/tests/System.DirectoryServices.Tests.csproj b/src/libraries/System.DirectoryServices/tests/System.DirectoryServices.Tests.csproj
index 7c86e128ac562..51fee5865b7ad 100644
--- a/src/libraries/System.DirectoryServices/tests/System.DirectoryServices.Tests.csproj
+++ b/src/libraries/System.DirectoryServices/tests/System.DirectoryServices.Tests.csproj
@@ -27,11 +27,9 @@
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp'">
     <Compile Include="System\DirectoryServices\DirectoryServicesTests.Windows.cs" />
     <Compile Include="System\DirectoryServices\ActiveDirectoryComInterop.cs" />
-  </ItemGroup>
-  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp'">
     <ProjectReference Include="..\src\System.DirectoryServices.csproj" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework'">
diff --git a/src/libraries/System.Drawing.Common/src/System.Drawing.Common.csproj b/src/libraries/System.Drawing.Common/src/System.Drawing.Common.csproj
index 5a34aa4d3ada0..65731f1d12904 100644
--- a/src/libraries/System.Drawing.Common/src/System.Drawing.Common.csproj
+++ b/src/libraries/System.Drawing.Common/src/System.Drawing.Common.csproj
@@ -3,7 +3,6 @@
     <DefineConstants>$(DefineConstants);DRAWING_NAMESPACE</DefineConstants>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <WarningsNotAsErrors>CS0618</WarningsNotAsErrors>
-    <DefineConstants Condition="'$(TargetsWindows)' == 'true'">$(DefineConstants);FEATURE_WINDOWS_SYSTEM_COLORS;FEATURE_SYSTEM_EVENTS</DefineConstants>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent);$(NetCoreAppMinimum)-windows;$(NetCoreAppMinimum)-Unix;$(NetCoreAppMinimum);netstandard2.0;$(NetFrameworkMinimum)</TargetFrameworks>
     <Nullable>enable</Nullable>
@@ -23,14 +22,16 @@ Unix support is disabled by default. See https://aka.ms/systemdrawingnonwindows
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'windows'">$(DefineConstants);FEATURE_WINDOWS_SYSTEM_COLORS;FEATURE_SYSTEM_EVENTS</DefineConstants>
     <IncludeInternalObsoleteAttribute Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) != '.NETFramework'">true</IncludeInternalObsoleteAttribute>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsAnyOS)' == 'true' and $([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) != '.NETFramework'">SR.SystemDrawingCommon_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) != '.NETFramework' and '$(TargetPlatformIdentifier)' == ''">SR.SystemDrawingCommon_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
   <ItemGroup Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'">
     <Compile Include="$(CoreLibSharedDir)System\Diagnostics\CodeAnalysis\RequiresUnreferencedCodeAttribute.cs" />
     <Compile Include="$(CoreLibSharedDir)System\Diagnostics\CodeAnalysis\UnconditionalSuppressMessageAttribute.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="System\Drawing\Bitmap.cs" />
     <Compile Include="System\Drawing\BitmapSuffixInSameAssemblyAttribute.cs" />
     <Compile Include="System\Drawing\BitmapSuffixInSatelliteAssemblyAttribute.cs" />
@@ -201,7 +202,7 @@ Unix support is disabled by default. See https://aka.ms/systemdrawingnonwindows
     </EmbeddedResource>
   </ItemGroup>
   <!-- Windows-specific -->
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="SRDescriptionAttribute.cs" />
     <Compile Include="System\Drawing\Bitmap.Windows.cs" />
     <Compile Include="System\Drawing\BitmapSelector.cs" />
@@ -331,23 +332,14 @@ Unix support is disabled by default. See https://aka.ms/systemdrawingnonwindows
              Link="Common\Interop\Windows\User32\Interop.WindowFromDC.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.HRESULT.cs"
              Link="Common\Interop\Windows\Interop.HRESULT.cs" />
-  </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true' and '$(TargetFrameworkIdentifier)' == '.NETCoreApp'">
     <Compile Include="$(CommonPath)Interop\Windows\Ole32\Interop.IStream.COMWrappers.cs"
              Link="Common\Interop\Windows\Ole32\Interop.IStream.COMWrappers.cs" />
     <Compile Include="System\Drawing\DrawingCom.COMWrappers.cs" />
     <Compile Include="System\Drawing\Icon.Windows.COMWrappers.cs" />
     <Compile Include="System\Drawing\Internal\GPStream.COMWrappers.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true' and '$(TargetFrameworkIdentifier)' != '.NETCoreApp'">
-    <Compile Include="$(CommonPath)Interop\Windows\Ole32\Interop.IStream.NoCOMWrappers.cs"
-             Link="Common\Interop\Windows\Ole32\Interop.IStream.NoCOMWrappers.cs" />
-    <Compile Include="System\Drawing\DrawingCom.NoCOMWrappers.cs" />
-    <Compile Include="System\Drawing\Icon.Windows.NoCOMWrappers.cs" />
-    <Compile Include="System\Drawing\Internal\GPStream.NoCOMWrappers.cs" />
-  </ItemGroup>
   <!-- Unix specific -->
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Compile Include="System\Drawing\Graphics.Unix.cs" />
     <Compile Include="System\Drawing\Icon.Unix.cs" />
     <Compile Include="System\Drawing\SystemFonts.Unix.cs" />
@@ -393,7 +385,7 @@ Unix support is disabled by default. See https://aka.ms/systemdrawingnonwindows
       <LogicalName>placeholder.ico</LogicalName>
     </EmbeddedResource>
   </ItemGroup>
-  <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0')) and '$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0')) and '$(TargetPlatformIdentifier)' != ''">
     <Compile Include="$(CommonPath)DisableRuntimeMarshalling.cs"
              Link="Common\DisableRuntimeMarshalling.cs" />
     <Compile Include="$(CommonPath)System\Runtime\InteropServices\HandleRefMarshaller.cs"
diff --git a/src/libraries/System.Drawing.Primitives/ref/System.Drawing.Primitives.csproj b/src/libraries/System.Drawing.Primitives/ref/System.Drawing.Primitives.csproj
index bfa339532ed75..0ade64252f550 100644
--- a/src/libraries/System.Drawing.Primitives/ref/System.Drawing.Primitives.csproj
+++ b/src/libraries/System.Drawing.Primitives/ref/System.Drawing.Primitives.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Drawing.Primitives/src/System.Drawing.Primitives.csproj b/src/libraries/System.Drawing.Primitives/src/System.Drawing.Primitives.csproj
index e8328af20cde9..dd2b9b692ad3a 100644
--- a/src/libraries/System.Drawing.Primitives/src/System.Drawing.Primitives.csproj
+++ b/src/libraries/System.Drawing.Primitives/src/System.Drawing.Primitives.csproj
@@ -1,10 +1,14 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <RootNamespace>System.Drawing</RootNamespace>
-    <DefineConstants Condition="'$(TargetsWindows)' == 'true'">$(DefineConstants);FEATURE_WINDOWS_SYSTEM_COLORS</DefineConstants>
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)</TargetFrameworks>
     <Nullable>enable</Nullable>
   </PropertyGroup>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
+  <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'windows'">$(DefineConstants);FEATURE_WINDOWS_SYSTEM_COLORS</DefineConstants>
+  </PropertyGroup>
   <ItemGroup>
     <Compile Include="System\Drawing\KnownColorNames.cs" />
     <Compile Include="System\Drawing\Point.cs" />
@@ -27,7 +31,7 @@
     <Compile Include="$(CommonPath)System\Drawing\SystemColors.cs"
              Link="System\Drawing\SystemColors.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
              Link="Common\Interop\Windows\Interop.Libraries.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\User32\Interop.GetSysColor.cs"
diff --git a/src/libraries/System.Dynamic.Runtime/ref/System.Dynamic.Runtime.csproj b/src/libraries/System.Dynamic.Runtime/ref/System.Dynamic.Runtime.csproj
index 17c5cc095dd34..766e1e7d3b4ec 100644
--- a/src/libraries/System.Dynamic.Runtime/ref/System.Dynamic.Runtime.csproj
+++ b/src/libraries/System.Dynamic.Runtime/ref/System.Dynamic.Runtime.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Dynamic.Runtime/src/System.Dynamic.Runtime.csproj b/src/libraries/System.Dynamic.Runtime/src/System.Dynamic.Runtime.csproj
index 152b87d25dd61..55eadef5a9a79 100644
--- a/src/libraries/System.Dynamic.Runtime/src/System.Dynamic.Runtime.csproj
+++ b/src/libraries/System.Dynamic.Runtime/src/System.Dynamic.Runtime.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Globalization.Calendars/ref/System.Globalization.Calendars.csproj b/src/libraries/System.Globalization.Calendars/ref/System.Globalization.Calendars.csproj
index ca034e36a686c..b53ef51fbacc2 100644
--- a/src/libraries/System.Globalization.Calendars/ref/System.Globalization.Calendars.csproj
+++ b/src/libraries/System.Globalization.Calendars/ref/System.Globalization.Calendars.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Globalization.Calendars/src/System.Globalization.Calendars.csproj b/src/libraries/System.Globalization.Calendars/src/System.Globalization.Calendars.csproj
index 4f2d15aa3b6a5..a9c43608342de 100644
--- a/src/libraries/System.Globalization.Calendars/src/System.Globalization.Calendars.csproj
+++ b/src/libraries/System.Globalization.Calendars/src/System.Globalization.Calendars.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Globalization.Extensions/ref/System.Globalization.Extensions.csproj b/src/libraries/System.Globalization.Extensions/ref/System.Globalization.Extensions.csproj
index 54c76201458d6..231fb39433fb3 100644
--- a/src/libraries/System.Globalization.Extensions/ref/System.Globalization.Extensions.csproj
+++ b/src/libraries/System.Globalization.Extensions/ref/System.Globalization.Extensions.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Globalization.Extensions/src/System.Globalization.Extensions.csproj b/src/libraries/System.Globalization.Extensions/src/System.Globalization.Extensions.csproj
index 495dad9cebeb7..6beae5c98dbd4 100644
--- a/src/libraries/System.Globalization.Extensions/src/System.Globalization.Extensions.csproj
+++ b/src/libraries/System.Globalization.Extensions/src/System.Globalization.Extensions.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="System.Runtime" />
diff --git a/src/libraries/System.Globalization/ref/System.Globalization.csproj b/src/libraries/System.Globalization/ref/System.Globalization.csproj
index 9a0c64de5b036..5cf1bb07a61ec 100644
--- a/src/libraries/System.Globalization/ref/System.Globalization.csproj
+++ b/src/libraries/System.Globalization/ref/System.Globalization.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Globalization/src/System.Globalization.csproj b/src/libraries/System.Globalization/src/System.Globalization.csproj
index 4f2d15aa3b6a5..a9c43608342de 100644
--- a/src/libraries/System.Globalization/src/System.Globalization.csproj
+++ b/src/libraries/System.Globalization/src/System.Globalization.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.IO.Compression.Brotli/ref/System.IO.Compression.Brotli.csproj b/src/libraries/System.IO.Compression.Brotli/ref/System.IO.Compression.Brotli.csproj
index bce17a52f8fce..662f5a31b64f5 100644
--- a/src/libraries/System.IO.Compression.Brotli/ref/System.IO.Compression.Brotli.csproj
+++ b/src/libraries/System.IO.Compression.Brotli/ref/System.IO.Compression.Brotli.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <Nullable>enable</Nullable>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System.IO.Compression.Brotli.cs" />
diff --git a/src/libraries/System.IO.Compression.Brotli/src/System.IO.Compression.Brotli.csproj b/src/libraries/System.IO.Compression.Brotli/src/System.IO.Compression.Brotli.csproj
index 80ad7a7940bb6..6786fda165831 100644
--- a/src/libraries/System.IO.Compression.Brotli/src/System.IO.Compression.Brotli.csproj
+++ b/src/libraries/System.IO.Compression.Brotli/src/System.IO.Compression.Brotli.csproj
@@ -6,9 +6,10 @@
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsAnyOS)' == 'true'">SR.IOCompressionBrotli_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == ''">SR.IOCompressionBrotli_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="$(CommonPath)Interop\Interop.Brotli.cs" />
     <!-- The native compression lib uses a BROTLI_BOOL type analogous to the Windows BOOL type -->
     <Compile Include="$(CommonPath)Interop\Windows\Interop.BOOL.cs" />
@@ -26,12 +27,12 @@
              Link="Common\Microsoft\Win32\SafeHandles\SafeBrotliHandle.cs" />
   </ItemGroup>
   <!-- Windows specific files -->
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
              Link="Common\Interop\Windows\Interop.Libraries.cs" />
   </ItemGroup>
   <!-- Unix specific files -->
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' ">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix' ">
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs"
              Link="Common\Interop\Unix\Interop.Libraries.cs" />
   </ItemGroup>
diff --git a/src/libraries/System.IO.Compression.ZipFile/ref/System.IO.Compression.ZipFile.csproj b/src/libraries/System.IO.Compression.ZipFile/ref/System.IO.Compression.ZipFile.csproj
index 1c175660be30d..a72c3f36f4229 100644
--- a/src/libraries/System.IO.Compression.ZipFile/ref/System.IO.Compression.ZipFile.csproj
+++ b/src/libraries/System.IO.Compression.ZipFile/ref/System.IO.Compression.ZipFile.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.IO.Compression.ZipFile/src/System.IO.Compression.ZipFile.csproj b/src/libraries/System.IO.Compression.ZipFile/src/System.IO.Compression.ZipFile.csproj
index 66827e87964fb..de869f13e9353 100644
--- a/src/libraries/System.IO.Compression.ZipFile/src/System.IO.Compression.ZipFile.csproj
+++ b/src/libraries/System.IO.Compression.ZipFile/src/System.IO.Compression.ZipFile.csproj
@@ -17,7 +17,7 @@
              Link="Common\System\IO\PathInternal.CaseSensitivity.cs" />
   </ItemGroup>
   <!-- Unix specific files -->
-  <ItemGroup Condition=" '$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true' ">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="System\IO\Compression\ZipFileExtensions.ZipArchive.Create.Unix.cs" />
     <Compile Include="System\IO\Compression\ZipFileExtensions.ZipArchiveEntry.Extract.Unix.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\Interop.IOErrors.cs"
diff --git a/src/libraries/System.IO.Compression.ZipFile/tests/System.IO.Compression.ZipFile.Tests.csproj b/src/libraries/System.IO.Compression.ZipFile/tests/System.IO.Compression.ZipFile.Tests.csproj
index 94aa77c9c9a6e..7e9194ebe8e68 100644
--- a/src/libraries/System.IO.Compression.ZipFile/tests/System.IO.Compression.ZipFile.Tests.csproj
+++ b/src/libraries/System.IO.Compression.ZipFile/tests/System.IO.Compression.ZipFile.Tests.csproj
@@ -36,7 +36,7 @@
     <Compile Include="$(CommonTestPath)System\IO\Compression\ZipTestHelper.cs"
              Link="Common\System\IO\Compression\ZipTestHelper.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true' ">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="ZipFile.Unix.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs" Link="Interop\Unix\Interop.Libraries.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.ChMod.cs" Link="Interop\Unix\System.Native\Interop.ChMod.cs" />
diff --git a/src/libraries/System.IO.Compression/ref/System.IO.Compression.csproj b/src/libraries/System.IO.Compression/ref/System.IO.Compression.csproj
index 8b14159415b7e..ff7cf6d8c3846 100644
--- a/src/libraries/System.IO.Compression/ref/System.IO.Compression.csproj
+++ b/src/libraries/System.IO.Compression/ref/System.IO.Compression.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.IO.Compression/src/System.IO.Compression.csproj b/src/libraries/System.IO.Compression/src/System.IO.Compression.csproj
index 8a33c737f13e6..4d5e69f94d8ab 100644
--- a/src/libraries/System.IO.Compression/src/System.IO.Compression.csproj
+++ b/src/libraries/System.IO.Compression/src/System.IO.Compression.csproj
@@ -44,13 +44,13 @@
              Link="Common\System\Threading\Tasks\TaskToApm.cs" />
   </ItemGroup>
   <!-- Windows specific files -->
-  <ItemGroup Condition=" '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\IO\Compression\ZipArchiveEntry.Windows.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
              Link="Common\Interop\Windows\Interop.Libraries.cs" />
   </ItemGroup>
   <!-- Unix specific files -->
-  <ItemGroup Condition=" '$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true' ">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="System\IO\Compression\ZipArchiveEntry.Unix.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs"
              Link="Common\Interop\Unix\Interop.Libraries.cs" />
diff --git a/src/libraries/System.IO.FileSystem.AccessControl/ref/System.IO.FileSystem.AccessControl.csproj b/src/libraries/System.IO.FileSystem.AccessControl/ref/System.IO.FileSystem.AccessControl.csproj
index 5aab0ab81639e..da1ac825505ff 100644
--- a/src/libraries/System.IO.FileSystem.AccessControl/ref/System.IO.FileSystem.AccessControl.csproj
+++ b/src/libraries/System.IO.FileSystem.AccessControl/ref/System.IO.FileSystem.AccessControl.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.IO.FileSystem.AccessControl/src/System.IO.FileSystem.AccessControl.csproj b/src/libraries/System.IO.FileSystem.AccessControl/src/System.IO.FileSystem.AccessControl.csproj
index e7a90eb3a6eb5..28465e91788be 100644
--- a/src/libraries/System.IO.FileSystem.AccessControl/src/System.IO.FileSystem.AccessControl.csproj
+++ b/src/libraries/System.IO.FileSystem.AccessControl/src/System.IO.FileSystem.AccessControl.csproj
@@ -5,11 +5,12 @@
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <AllowUnsafeBlocks Condition="'$(TargetsWindows)' == 'true'">true</AllowUnsafeBlocks>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsWindows)' != 'true'">SR.PlatformNotSupported_AccessControl</GeneratePlatformNotSupportedAssemblyMessage>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <AllowUnsafeBlocks Condition="'$(TargetPlatformIdentifier)' == 'windows'">true</AllowUnsafeBlocks>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' != 'windows'">SR.PlatformNotSupported_AccessControl</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
   <!-- Source includes -->
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)DisableRuntimeMarshalling.cs"
              Link="Common\DisableRuntimeMarshalling.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Errors.cs"
@@ -88,20 +89,20 @@
              Link="Common\System\IO\FileSystem.DirectoryCreation.Windows.cs" />
   </ItemGroup>
   <ItemGroup>
-    <Reference Include="System.Buffers" Condition="'$(TargetsWindows)' == 'true'" />
-    <Reference Include="System.Collections" Condition="'$(TargetsWindows)' == 'true'" />
+    <Reference Include="System.Buffers" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
+    <Reference Include="System.Collections" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Reference Include="System.Collections.NonGeneric" />
     <Reference Include="System.Diagnostics.Debug" />
     <Reference Include="System.IO.FileSystem" />
-    <Reference Include="System.Memory" Condition="'$(TargetsWindows)' == 'true'" />
+    <Reference Include="System.Memory" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Reference Include="System.Resources.ResourceManager" />
     <Reference Include="System.Runtime" />
-    <Reference Include="System.Runtime.CompilerServices.Unsafe" Condition="'$(TargetsWindows)' == 'true'" />
+    <Reference Include="System.Runtime.CompilerServices.Unsafe" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Reference Include="System.Runtime.Extensions" />
     <Reference Include="System.Runtime.Handles" />
-    <Reference Include="System.Runtime.InteropServices" Condition="'$(TargetsWindows)' == 'true'" />
+    <Reference Include="System.Runtime.InteropServices" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Reference Include="System.Security.AccessControl" />
     <Reference Include="System.Security.Principal.Windows" />
-    <Reference Include="System.Threading.Tasks" Condition="'$(TargetsWindows)' == 'true'" />
+    <Reference Include="System.Threading.Tasks" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
   </ItemGroup>
 </Project>
diff --git a/src/libraries/System.IO.FileSystem.DriveInfo/ref/System.IO.FileSystem.DriveInfo.csproj b/src/libraries/System.IO.FileSystem.DriveInfo/ref/System.IO.FileSystem.DriveInfo.csproj
index 9f6b2e37bcd69..bd014e7f4b1cd 100644
--- a/src/libraries/System.IO.FileSystem.DriveInfo/ref/System.IO.FileSystem.DriveInfo.csproj
+++ b/src/libraries/System.IO.FileSystem.DriveInfo/ref/System.IO.FileSystem.DriveInfo.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.IO.FileSystem.DriveInfo/src/System.IO.FileSystem.DriveInfo.csproj b/src/libraries/System.IO.FileSystem.DriveInfo/src/System.IO.FileSystem.DriveInfo.csproj
index 7cdd5006490a0..686750ba9496f 100644
--- a/src/libraries/System.IO.FileSystem.DriveInfo/src/System.IO.FileSystem.DriveInfo.csproj
+++ b/src/libraries/System.IO.FileSystem.DriveInfo/src/System.IO.FileSystem.DriveInfo.csproj
@@ -19,7 +19,7 @@
     <Compile Include="System\IO\DriveInfo.UnixOrDefault.cs" />
     <Compile Include="System\IO\DriveInfo.Default.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\IO\Error.cs" />
     <Compile Include="System\IO\DriveInfo.Windows.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
@@ -53,7 +53,7 @@
     <Compile Include="$(CoreLibSharedDir)System\IO\DriveInfoInternal.Windows.cs"
              Link="Common\System\IO\DriveInfoInternal.Windows.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Compile Include="System\IO\DriveInfo.UnixOrDefault.cs" />
     <Compile Include="System\IO\DriveInfo.Unix.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs"
diff --git a/src/libraries/System.IO.FileSystem.DriveInfo/tests/System.IO.FileSystem.DriveInfo.Tests.csproj b/src/libraries/System.IO.FileSystem.DriveInfo/tests/System.IO.FileSystem.DriveInfo.Tests.csproj
index fa6aaa94a54c8..00d1afd3c9411 100644
--- a/src/libraries/System.IO.FileSystem.DriveInfo/tests/System.IO.FileSystem.DriveInfo.Tests.csproj
+++ b/src/libraries/System.IO.FileSystem.DriveInfo/tests/System.IO.FileSystem.DriveInfo.Tests.csproj
@@ -3,10 +3,10 @@
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent)-Browser</TargetFrameworks>
   </PropertyGroup>
   <ItemGroup>
-    <Compile Include="DriveInfo.Unix.Tests.cs" Condition="'$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true'" />
-    <Compile Include="DriveInfo.Windows.Tests.cs" Condition="'$(TargetsWindows)' == 'true'" />
-    <Compile Include="VirtualDrives.Windows.Tests.cs" Condition="'$(TargetsWindows)' == 'true'" />
-    <Compile Include="$(CommonTestPath)System\IO\VirtualDriveHelper.Windows.cs" Link="Common\System\IO\VirtualDriveHelper.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="DriveInfo.Unix.Tests.cs" Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Browser'" />
+    <Compile Include="DriveInfo.Windows.Tests.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
+    <Compile Include="VirtualDrives.Windows.Tests.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
+    <Compile Include="$(CommonTestPath)System\IO\VirtualDriveHelper.Windows.cs" Link="Common\System\IO\VirtualDriveHelper.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="$(CommonTestPath)TestUtilities\System\DisableParallelizationPerAssembly.cs" />
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.IO.FileSystem.Primitives/ref/System.IO.FileSystem.Primitives.csproj b/src/libraries/System.IO.FileSystem.Primitives/ref/System.IO.FileSystem.Primitives.csproj
index 31a3c74ddc948..d3418bd9442f3 100644
--- a/src/libraries/System.IO.FileSystem.Primitives/ref/System.IO.FileSystem.Primitives.csproj
+++ b/src/libraries/System.IO.FileSystem.Primitives/ref/System.IO.FileSystem.Primitives.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.IO.FileSystem.Primitives/src/System.IO.FileSystem.Primitives.csproj b/src/libraries/System.IO.FileSystem.Primitives/src/System.IO.FileSystem.Primitives.csproj
index 94d0c64013048..36c7cb1bdde2a 100644
--- a/src/libraries/System.IO.FileSystem.Primitives/src/System.IO.FileSystem.Primitives.csproj
+++ b/src/libraries/System.IO.FileSystem.Primitives/src/System.IO.FileSystem.Primitives.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.IO.FileSystem.Watcher/ref/System.IO.FileSystem.Watcher.csproj b/src/libraries/System.IO.FileSystem.Watcher/ref/System.IO.FileSystem.Watcher.csproj
index 2ee74d6667a9d..d9fca4d4667f2 100644
--- a/src/libraries/System.IO.FileSystem.Watcher/ref/System.IO.FileSystem.Watcher.csproj
+++ b/src/libraries/System.IO.FileSystem.Watcher/ref/System.IO.FileSystem.Watcher.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.IO.FileSystem.Watcher/src/System.IO.FileSystem.Watcher.csproj b/src/libraries/System.IO.FileSystem.Watcher/src/System.IO.FileSystem.Watcher.csproj
index f8a57395aa6ef..b31c940615c08 100644
--- a/src/libraries/System.IO.FileSystem.Watcher/src/System.IO.FileSystem.Watcher.csproj
+++ b/src/libraries/System.IO.FileSystem.Watcher/src/System.IO.FileSystem.Watcher.csproj
@@ -1,14 +1,15 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Linux;$(NetCoreAppCurrent);$(NetCoreAppCurrent)-OSX;$(NetCoreAppCurrent)-MacCatalyst;$(NetCoreAppCurrent)-FreeBSD</TargetFrameworks>
+    <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Linux;$(NetCoreAppCurrent)-OSX;$(NetCoreAppCurrent)-MacCatalyst;$(NetCoreAppCurrent)-FreeBSD;$(NetCoreAppCurrent)</TargetFrameworks>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsAnyOS)' == 'true'">SR.FileSystemWatcher_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == ''">SR.FileSystemWatcher_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="System\HResults.cs" />
     <Compile Include="System\IO\ErrorEventArgs.cs" />
     <Compile Include="System\IO\ErrorEventHandler.cs" />
@@ -32,7 +33,7 @@
     <Compile Include="$(CommonPath)System\Text\ValueStringBuilder.cs"
              Link="Common\System\Text\ValueStringBuilder.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)System\IO\PathInternal.Windows.cs"
              Link="Common\System\IO\PathInternal.Windows.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
@@ -50,13 +51,11 @@
     </Compile>
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.CloseHandle.cs"
              Link="Common\Interop\Windows\Interop.CloseHandle.cs" />
-  </ItemGroup>
-  <!-- Windows : Win32 only -->
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.CreateFile.cs"
              Link="Common\Interop\Windows\Interop.CreateFile.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsUnix)' == 'true'">
+  <!-- Unix -->
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows'">
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs"
              Link="Common\Interop\Unix\Interop.Libraries.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.Read.cs"
@@ -70,7 +69,7 @@
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.PathConf.cs"
              Link="Common\Interop\Unix\Interop.PathConf.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsLinux)' == 'true' or '$(TargetsFreeBSD)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Linux' or '$(TargetPlatformIdentifier)' == 'FreeBSD'">
     <Compile Include="System\IO\FileSystemWatcher.Linux.cs" />
     <Compile Include="$(CommonPath)Interop\Linux\System.Native\Interop.INotify.cs"
              Link="Common\Interop\Linux\Interop.inotify.cs" />
@@ -81,7 +80,7 @@
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.Stat.cs"
              Link="Common\Interop\Unix\Interop.Stat.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsOSX)' == 'true' or '$(TargetsMacCatalyst)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'OSX' or '$(TargetPlatformIdentifier)' == 'MacCatalyst'">
     <Compile Include="System\IO\FileSystemWatcher.OSX.cs" />
     <Compile Include="$(CoreLibSharedDir)System\IO\FileSystem.Exists.Unix.cs"
              Link="System\IO\FileSystem.Exists.Unix.cs" />
@@ -110,7 +109,7 @@
     <Compile Include="$(CommonPath)System\Text\ValueUtf8Converter.cs"
              Link="Common\System\Text\ValueUtf8Converter.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnknownUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'UnknownUnix'">
     <Compile Include="System\IO\FileSystemWatcher.UnknownUnix.cs" />
   </ItemGroup>
   <ItemGroup>
@@ -126,7 +125,7 @@
     <Reference Include="System.Threading" />
     <Reference Include="System.Threading.Overlapped" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows'">
     <Reference Include="System.Collections" />
     <Reference Include="System.Threading.Thread" />
   </ItemGroup>
diff --git a/src/libraries/System.IO.FileSystem.Watcher/tests/System.IO.FileSystem.Watcher.Tests.csproj b/src/libraries/System.IO.FileSystem.Watcher/tests/System.IO.FileSystem.Watcher.Tests.csproj
index 7bbb9eb5986b7..381f9dfc4e4c9 100644
--- a/src/libraries/System.IO.FileSystem.Watcher/tests/System.IO.FileSystem.Watcher.Tests.csproj
+++ b/src/libraries/System.IO.FileSystem.Watcher/tests/System.IO.FileSystem.Watcher.Tests.csproj
@@ -46,15 +46,15 @@
     <Compile Include="$(CommonPath)System\Text\ValueStringBuilder.cs"
              Link="Common\System\Text\ValueStringBuilder.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition=" '$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)System\IO\PathInternal.Windows.cs"
              Link="Common\System\IO\PathInternal.Windows.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'windows'">
     <Compile Include="$(CommonPath)System\IO\PathInternal.Unix.cs"
              Link="Common\System\IO\PathInternal.Unix.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsLinux)' == 'true' or '$(TargetsOSX)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Linux' or '$(TargetPlatformIdentifier)' == 'OSX'">
     <Compile Include="FileSystemWatcher.Unix.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs"
              Link="Common\Interop\Unix\Interop.Libraries.cs" />
diff --git a/src/libraries/System.IO.FileSystem/ref/System.IO.FileSystem.csproj b/src/libraries/System.IO.FileSystem/ref/System.IO.FileSystem.csproj
index 0ceabbf133b37..cf4cf19f19d05 100644
--- a/src/libraries/System.IO.FileSystem/ref/System.IO.FileSystem.csproj
+++ b/src/libraries/System.IO.FileSystem/ref/System.IO.FileSystem.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.IO.FileSystem/src/System.IO.FileSystem.csproj b/src/libraries/System.IO.FileSystem/src/System.IO.FileSystem.csproj
index 91447b65b71e6..8d75eca3bbe2b 100644
--- a/src/libraries/System.IO.FileSystem/src/System.IO.FileSystem.csproj
+++ b/src/libraries/System.IO.FileSystem/src/System.IO.FileSystem.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.IO.FileSystem/tests/DisabledFileLockingTests/System.IO.FileSystem.DisabledFileLocking.Tests.csproj b/src/libraries/System.IO.FileSystem/tests/DisabledFileLockingTests/System.IO.FileSystem.DisabledFileLocking.Tests.csproj
index cefda71097791..99230625e3c9d 100644
--- a/src/libraries/System.IO.FileSystem/tests/DisabledFileLockingTests/System.IO.FileSystem.DisabledFileLocking.Tests.csproj
+++ b/src/libraries/System.IO.FileSystem/tests/DisabledFileLockingTests/System.IO.FileSystem.DisabledFileLocking.Tests.csproj
@@ -24,7 +24,7 @@
     <Compile Include="$(CommonTestPath)System\IO\PathFeatures.cs" Link="Common\System\IO\PathFeatures.cs" />
     <Compile Include="$(CommonTestPath)TestUtilities\System\DisableParallelization.cs" Link="Common\TestUtilities\System\DisableParallelization.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup>
     <Compile Remove="..\**\*.Windows.cs" />
     <Compile Remove="..\**\*.Browser.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs" Link="Interop\Unix\Interop.Libraries.cs" />
diff --git a/src/libraries/System.IO.FileSystem/tests/System.IO.FileSystem.Tests.csproj b/src/libraries/System.IO.FileSystem/tests/System.IO.FileSystem.Tests.csproj
index 967338535cd01..053c913a45620 100644
--- a/src/libraries/System.IO.FileSystem/tests/System.IO.FileSystem.Tests.csproj
+++ b/src/libraries/System.IO.FileSystem/tests/System.IO.FileSystem.Tests.csproj
@@ -71,12 +71,12 @@
     <Compile Include="RandomAccess\WriteGather.cs" />
     <Compile Include="RandomAccess\WriteGatherAsync.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Compile Include="FileSystemTest.Unix.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs" Link="Interop\Unix\Interop.Libraries.cs" />
     <Compile Include="FileStream\ctor_options.Unix.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="Directory\Delete.Windows.cs" />
     <Compile Include="File\EncryptDecrypt.Windows.cs" />
     <Compile Include="FileSystemTest.Windows.cs" />
@@ -103,7 +103,7 @@
     <ProjectReference Include="$(LibrariesProjectRoot)System.ServiceProcess.ServiceController\src\System.ServiceProcess.ServiceController.csproj" />
     <ProjectReference Include="$(LibrariesProjectRoot)System.IO.FileSystem.AccessControl\src\System.IO.FileSystem.AccessControl.csproj" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="FileSystemTest.Browser.cs" />
     <Compile Include="FileStream\ctor_options.Browser.cs" />
   </ItemGroup>
diff --git a/src/libraries/System.IO.IsolatedStorage/ref/System.IO.IsolatedStorage.csproj b/src/libraries/System.IO.IsolatedStorage/ref/System.IO.IsolatedStorage.csproj
index 39903d836f807..167ebaf32a1f5 100644
--- a/src/libraries/System.IO.IsolatedStorage/ref/System.IO.IsolatedStorage.csproj
+++ b/src/libraries/System.IO.IsolatedStorage/ref/System.IO.IsolatedStorage.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.IO.IsolatedStorage/src/System.IO.IsolatedStorage.csproj b/src/libraries/System.IO.IsolatedStorage/src/System.IO.IsolatedStorage.csproj
index 40664e4864329..025f454662f44 100644
--- a/src/libraries/System.IO.IsolatedStorage/src/System.IO.IsolatedStorage.csproj
+++ b/src/libraries/System.IO.IsolatedStorage/src/System.IO.IsolatedStorage.csproj
@@ -1,12 +1,14 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent)</TargetFrameworks>
-	<Nullable>enable</Nullable>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsAnyOS)' == 'true'">SR.IsolatedStorage_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == ''">SR.IsolatedStorage_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="System\IO\IsolatedStorage\IsolatedStorageException.cs" />
     <Compile Include="System\IO\IsolatedStorage\IsolatedStorageFile.cs" />
     <Compile Include="System\IO\IsolatedStorage\IsolatedStorageFileStream.cs" />
@@ -18,24 +20,22 @@
     <Compile Include="$(CommonPath)System\Security\IdentityHelper.cs"
              Link="Common\System\Security\IdentityHelper.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\IO\IsolatedStorage\Helper.Win32.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Compile Include="System\IO\IsolatedStorage\Helper.Unix.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true'">
+  <ItemGroup>
     <Reference Include="System.IO.FileSystem" />
+    <Reference Include="System.IO.FileSystem.AccessControl" />
     <Reference Include="System.Linq" />
+    <Reference Include="System.Runtime" />
     <Reference Include="System.Runtime.Extensions" />
+    <Reference Include="System.Security.AccessControl" />
     <Reference Include="System.Security.Cryptography" />
     <Reference Include="System.Security.Cryptography.Algorithms" />
-    <Reference Include="System.Threading" />
-  </ItemGroup>
-  <ItemGroup>
-    <Reference Include="System.IO.FileSystem.AccessControl" />
-    <Reference Include="System.Runtime" />
-    <Reference Include="System.Security.AccessControl" />
     <Reference Include="System.Security.Principal.Windows" />
+    <Reference Include="System.Threading" />
   </ItemGroup>
 </Project>
diff --git a/src/libraries/System.IO.IsolatedStorage/tests/System.IO.IsolatedStorage.Tests.csproj b/src/libraries/System.IO.IsolatedStorage/tests/System.IO.IsolatedStorage.Tests.csproj
index 6f9c8a9719515..b075376fa8bf8 100644
--- a/src/libraries/System.IO.IsolatedStorage/tests/System.IO.IsolatedStorage.Tests.csproj
+++ b/src/libraries/System.IO.IsolatedStorage/tests/System.IO.IsolatedStorage.Tests.csproj
@@ -13,11 +13,11 @@
              Link="Internals\Helper.Win32Unix.cs" />
     <Compile Include="System\IO\IsolatedStorage\HelperTests.Win32Unix.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="..\src\System\IO\IsolatedStorage\Helper.Win32.cs"
              Link="Internals\Helper.Win32.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="..\src\System\IO\IsolatedStorage\Helper.Unix.cs"
              Link="Internals\Helper.Unix.cs" />
   </ItemGroup>
diff --git a/src/libraries/System.IO.MemoryMappedFiles/ref/System.IO.MemoryMappedFiles.csproj b/src/libraries/System.IO.MemoryMappedFiles/ref/System.IO.MemoryMappedFiles.csproj
index 328e5db6032a5..06957485174c3 100644
--- a/src/libraries/System.IO.MemoryMappedFiles/ref/System.IO.MemoryMappedFiles.csproj
+++ b/src/libraries/System.IO.MemoryMappedFiles/ref/System.IO.MemoryMappedFiles.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <Nullable>enable</Nullable>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System.IO.MemoryMappedFiles.cs" />
diff --git a/src/libraries/System.IO.MemoryMappedFiles/src/System.IO.MemoryMappedFiles.csproj b/src/libraries/System.IO.MemoryMappedFiles/src/System.IO.MemoryMappedFiles.csproj
index 6285027286b7c..156867fd41bc3 100644
--- a/src/libraries/System.IO.MemoryMappedFiles/src/System.IO.MemoryMappedFiles.csproj
+++ b/src/libraries/System.IO.MemoryMappedFiles/src/System.IO.MemoryMappedFiles.csproj
@@ -22,7 +22,7 @@
     <Compile Include="$(CommonPath)DisableRuntimeMarshalling.cs"
              Link="Common\DisableRuntimeMarshalling.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\IO\MemoryMappedFiles\Interop.Windows.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.CreateFileMapping.cs"
              Link="Common\Interop\Windows\Interop.CreateFileMapping.cs" />
@@ -81,7 +81,7 @@
     <Compile Include="System\IO\MemoryMappedFiles\MemoryMappedFile.Windows.cs" />
     <Compile Include="System\IO\MemoryMappedFiles\MemoryMappedView.Windows.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true' ">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Browser' ">
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs"
              Link="Common\Interop\Unix\Interop.Libraries.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Errors.cs"
diff --git a/src/libraries/System.IO.MemoryMappedFiles/tests/System.IO.MemoryMappedFiles.Tests.csproj b/src/libraries/System.IO.MemoryMappedFiles/tests/System.IO.MemoryMappedFiles.Tests.csproj
index 92042aa78f2d3..614f9b602b1e1 100644
--- a/src/libraries/System.IO.MemoryMappedFiles/tests/System.IO.MemoryMappedFiles.Tests.csproj
+++ b/src/libraries/System.IO.MemoryMappedFiles/tests/System.IO.MemoryMappedFiles.Tests.csproj
@@ -15,8 +15,8 @@
     <Compile Include="MemoryMappedViewStream.Tests.cs" />
     <Compile Include="MemoryMappedViewAccessor.Tests.cs" />
     <Compile Include="MemoryMappedFilesTestsBase.cs" />
-    <Compile Include="MemoryMappedFilesTestsBase.Unix.cs" Condition="'$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true'" />
-    <Compile Include="MemoryMappedFilesTestsBase.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="MemoryMappedFilesTestsBase.Unix.cs" Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Browser'" />
+    <Compile Include="MemoryMappedFilesTestsBase.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="$(CommonTestPath)System\IO\TempFile.cs" Link="Common\System\IO\TempFile.cs" />
     <Compile Include="SafeMemoryMappedViewHandleTests.cs" />
     <Compile Include="XunitAssemblyAttributes.cs" />
diff --git a/src/libraries/System.IO.Pipes.AccessControl/ref/System.IO.Pipes.AccessControl.csproj b/src/libraries/System.IO.Pipes.AccessControl/ref/System.IO.Pipes.AccessControl.csproj
index 685a31dbdf26a..7a5d6dbd57b7f 100644
--- a/src/libraries/System.IO.Pipes.AccessControl/ref/System.IO.Pipes.AccessControl.csproj
+++ b/src/libraries/System.IO.Pipes.AccessControl/ref/System.IO.Pipes.AccessControl.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.IO.Pipes.AccessControl/src/System.IO.Pipes.AccessControl.csproj b/src/libraries/System.IO.Pipes.AccessControl/src/System.IO.Pipes.AccessControl.csproj
index 5e08c91b93806..34382fb608231 100644
--- a/src/libraries/System.IO.Pipes.AccessControl/src/System.IO.Pipes.AccessControl.csproj
+++ b/src/libraries/System.IO.Pipes.AccessControl/src/System.IO.Pipes.AccessControl.csproj
@@ -6,14 +6,15 @@
 
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsWindows)' != 'true'">SR.PlatformNotSupported_AccessControl</GeneratePlatformNotSupportedAssemblyMessage>
-    <IsPartialFacadeAssembly Condition="'$(TargetsWindows)' == 'true'">true</IsPartialFacadeAssembly>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <IsPartialFacadeAssembly Condition="'$(TargetPlatformIdentifier)' == 'windows'">true</IsPartialFacadeAssembly>
     <OmitResources Condition="'$(IsPartialFacadeAssembly)' == 'true'">true</OmitResources>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' != 'windows'">SR.PlatformNotSupported_AccessControl</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
 
   <ItemGroup>
     <ProjectReference Include="$(LibrariesProjectRoot)System.IO.Pipes\src\System.IO.Pipes.csproj">
-      <SkipUseReferenceAssembly Condition="'$(TargetsWindows)' == 'true'">true</SkipUseReferenceAssembly>
+      <SkipUseReferenceAssembly Condition="'$(TargetPlatformIdentifier)' == 'windows'">true</SkipUseReferenceAssembly>
     </ProjectReference>
     <Reference Include="System.Runtime" />
     <Reference Include="System.Security.AccessControl" />
diff --git a/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.csproj b/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.csproj
index bc664b2c29020..adef3b2144fc5 100644
--- a/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.csproj
+++ b/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.IO.Pipes/src/System.IO.Pipes.csproj b/src/libraries/System.IO.Pipes/src/System.IO.Pipes.csproj
index 0cf60c20c9a1c..e3e522f09b61f 100644
--- a/src/libraries/System.IO.Pipes/src/System.IO.Pipes.csproj
+++ b/src/libraries/System.IO.Pipes/src/System.IO.Pipes.csproj
@@ -5,11 +5,13 @@
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent)</TargetFrameworks>
     <Nullable>enable</Nullable>
   </PropertyGroup>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsAnyOS)' == 'true'">SR.Pipes_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == ''">SR.Pipes_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
   <!-- Compiled Source Files -->
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="Microsoft\Win32\SafeHandles\SafePipeHandle.cs" />
     <Compile Include="System\IO\Error.cs" />
     <Compile Include="System\IO\Pipes\AnonymousPipeClientStream.cs" />
@@ -26,7 +28,7 @@
     <Compile Include="$(CommonPath)System\Threading\Tasks\TaskToApm.cs"
              Link="Common\System\Threading\Tasks\TaskToApm.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
              Link="Common\Interop\Windows\Interop.Libraries.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.CloseHandle.cs"
@@ -108,14 +110,14 @@
     <Compile Include="System\IO\Pipes\PipeStream.Windows.cs" />
   </ItemGroup>
   <!-- Windows : Win32 only -->
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.CreateNamedPipeClient.cs"
              Link="Common\Interop\Windows\Interop.CreateNamedPipeClient.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.LoadLibraryEx_IntPtr.cs"
              Link="Common\Interop\Windows\Interop.LoadLibraryEx_IntPtr.cs" />
     <Compile Include="System\IO\Pipes\NamedPipeServerStream.Win32.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Compile Include="Microsoft\Win32\SafeHandles\SafePipeHandle.Unix.cs" />
     <Compile Include="System\IO\Pipes\AnonymousPipeServerStream.Unix.cs" />
     <Compile Include="System\IO\Pipes\NamedPipeClientStream.Unix.cs" />
@@ -177,11 +179,11 @@
     <Reference Include="System.Threading" />
     <Reference Include="System.Threading.Overlapped" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Reference Include="System.Collections.NonGeneric" />
     <Reference Include="System.Security.Claims" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Reference Include="Microsoft.Win32.Primitives" />
     <Reference Include="System.IO.FileSystem" />
     <Reference Include="System.Net.Primitives" />
diff --git a/src/libraries/System.IO.Pipes/tests/System.IO.Pipes.Tests.csproj b/src/libraries/System.IO.Pipes/tests/System.IO.Pipes.Tests.csproj
index 52ce3056b534d..dcec96f7ec54a 100644
--- a/src/libraries/System.IO.Pipes/tests/System.IO.Pipes.Tests.csproj
+++ b/src/libraries/System.IO.Pipes/tests/System.IO.Pipes.Tests.csproj
@@ -10,7 +10,7 @@
     <Compile Include="AssemblyInfo.cs" />
     <Compile Include="XunitAssemblyAttributes.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="AnonymousPipeTests\AnonymousPipeTest.CreateServer.cs" />
     <Compile Include="AnonymousPipeTests\AnonymousPipeTest.CreateClient.cs" />
     <Compile Include="AnonymousPipeTests\AnonymousPipeTest.CrossProcess.cs" />
@@ -23,7 +23,7 @@
     <Compile Include="PipeStreamConformanceTests.cs" />
     <Compile Include="$(CommonTestPath)System\Threading\Tasks\TaskTimeoutExtensions.cs" Link="Common\System\Threading\Tasks\TaskTimeoutExtensions.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="NamedPipeTests\NamedPipeTest.CurrentUserOnly.cs" />
     <Compile Include="NamedPipeTests\NamedPipeTest.CurrentUserOnly.Windows.cs" />
     <Compile Include="NamedPipeTests\NamedPipeTest.RunAsClient.Windows.cs" />
@@ -35,7 +35,7 @@
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.GetNamedPipeHandleState.cs" Link="Common\Interop\Windows\Interop.GetNamedPipeHandleState.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.MaxLengths.cs" Link="Common\Interop\Windows\Interop.MaxLengths.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Compile Include="NamedPipeTests\NamedPipeTest.CurrentUserOnly.Unix.cs" />
     <Compile Include="NamedPipeTests\NamedPipeTest.UnixDomainSockets.cs" />
     <Compile Include="NamedPipeTests\NamedPipeTest.RunAsClient.Unix.cs" />
diff --git a/src/libraries/System.IO.Ports/src/System.IO.Ports.csproj b/src/libraries/System.IO.Ports/src/System.IO.Ports.csproj
index 6dc6c00f09d76..67e40c9fef6a6 100644
--- a/src/libraries/System.IO.Ports/src/System.IO.Ports.csproj
+++ b/src/libraries/System.IO.Ports/src/System.IO.Ports.csproj
@@ -14,11 +14,12 @@ System.IO.Ports.SerialPort</PackageDescription>
 
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
     <IsPartialFacadeAssembly Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETFramework'">true</IsPartialFacadeAssembly>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetsAnyOS)' == 'true'">SR.PlatformNotSupported_IOPorts</GeneratePlatformNotSupportedAssemblyMessage>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetPlatformIdentifier)' == ''">SR.PlatformNotSupported_IOPorts</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
 
-  <ItemGroup Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="System\IO\Ports\Handshake.cs" />
     <Compile Include="System\IO\Ports\InternalResources.cs" />
     <Compile Include="System\IO\Ports\Parity.cs" />
@@ -36,13 +37,12 @@ System.IO.Ports.SerialPort</PackageDescription>
     <Compile Include="System\IO\Ports\StopBits.cs" />
   </ItemGroup>
 
-
-  <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0')) and '$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0')) and '$(TargetPlatformIdentifier)' != ''">
     <Compile Include="$(CommonPath)DisableRuntimeMarshalling.cs"
              Link="Common\DisableRuntimeMarshalling.cs" />
   </ItemGroup>
 
-  <ItemGroup Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\IO\Ports\SerialStream.Windows.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.DCB.cs"
              Link="Common\Interop\Windows\Kernel32\Interop.DCB.cs" />
@@ -122,7 +122,7 @@ System.IO.Ports.SerialPort</PackageDescription>
              Link="Common\Interop\Windows\Kernel32\Interop.FileOperations.cs" />
   </ItemGroup>
 
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Compile Include="System\IO\Ports\SafeSerialDeviceHandle.Unix.cs" />
     <Compile Include="System\IO\Ports\SerialPort.Unix.cs" />
     <Compile Include="System\IO\Ports\SerialStream.Unix.cs" />
@@ -144,17 +144,17 @@ System.IO.Ports.SerialPort</PackageDescription>
 
   <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp'">
     <Reference Include="Microsoft.Win32.Primitives" />
-    <Reference Include="Microsoft.Win32.Registry" Condition="'$(TargetsWindows)' == 'true'" />
+    <Reference Include="Microsoft.Win32.Registry" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Reference Include="System.Collections" />
-    <Reference Include="System.Collections.Concurrent" Condition="'$(TargetsUnix)' == 'true'" />
+    <Reference Include="System.Collections.Concurrent" Condition="'$(TargetPlatformIdentifier)' == 'Unix'" />
     <Reference Include="System.ComponentModel.Primitives" />
     <Reference Include="System.Memory" />
     <Reference Include="System.Net.Primitives" />
-    <Reference Include="System.Net.Sockets" Condition="'$(TargetsUnix)' == 'true'" />
+    <Reference Include="System.Net.Sockets" Condition="'$(TargetPlatformIdentifier)' == 'Unix'" />
     <Reference Include="System.Runtime" />
     <Reference Include="System.Runtime.CompilerServices.Unsafe" />
     <Reference Include="System.Runtime.InteropServices" />
-    <Reference Include="System.Runtime.InteropServices.RuntimeInformation" Condition="'$(TargetsUnix)' == 'true'" />
+    <Reference Include="System.Runtime.InteropServices.RuntimeInformation" Condition="'$(TargetPlatformIdentifier)' == 'Unix'" />
     <Reference Include="System.Text.Encoding.Extensions" />
     <Reference Include="System.Threading" />
     <Reference Include="System.Threading.Thread" />
diff --git a/src/libraries/System.IO.Ports/tests/System.IO.Ports.Tests.csproj b/src/libraries/System.IO.Ports/tests/System.IO.Ports.Tests.csproj
index 36756fdbb541d..9a1592778a7dc 100644
--- a/src/libraries/System.IO.Ports/tests/System.IO.Ports.Tests.csproj
+++ b/src/libraries/System.IO.Ports/tests/System.IO.Ports.Tests.csproj
@@ -109,7 +109,7 @@
     <Compile Include="Support\PortsTest.cs" />
     <Compile Include="Support\TestEventHandler.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true' or '$(TargetFrameworkIdentifier)' == '.NETFramework'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows' or '$(TargetFrameworkIdentifier)' == '.NETFramework'">
     <Compile Include="SerialPort\DosDevices.cs" />
     <Compile Include="SerialPort\PortName.cs" />
     <Compile Include="SerialPort\OpenDevices.cs" />
diff --git a/src/libraries/System.IO.UnmanagedMemoryStream/ref/System.IO.UnmanagedMemoryStream.csproj b/src/libraries/System.IO.UnmanagedMemoryStream/ref/System.IO.UnmanagedMemoryStream.csproj
index 0ee67eedafd72..af369779ebac8 100644
--- a/src/libraries/System.IO.UnmanagedMemoryStream/ref/System.IO.UnmanagedMemoryStream.csproj
+++ b/src/libraries/System.IO.UnmanagedMemoryStream/ref/System.IO.UnmanagedMemoryStream.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.IO.UnmanagedMemoryStream/src/System.IO.UnmanagedMemoryStream.csproj b/src/libraries/System.IO.UnmanagedMemoryStream/src/System.IO.UnmanagedMemoryStream.csproj
index 4f2d15aa3b6a5..a9c43608342de 100644
--- a/src/libraries/System.IO.UnmanagedMemoryStream/src/System.IO.UnmanagedMemoryStream.csproj
+++ b/src/libraries/System.IO.UnmanagedMemoryStream/src/System.IO.UnmanagedMemoryStream.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.IO/ref/System.IO.csproj b/src/libraries/System.IO/ref/System.IO.csproj
index 7439befee6f57..0ea49f44dad2c 100644
--- a/src/libraries/System.IO/ref/System.IO.csproj
+++ b/src/libraries/System.IO/ref/System.IO.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.IO/src/System.IO.csproj b/src/libraries/System.IO/src/System.IO.csproj
index 3b108d6826762..e2eb3417533b6 100644
--- a/src/libraries/System.IO/src/System.IO.csproj
+++ b/src/libraries/System.IO/src/System.IO.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Linq.Expressions/ref/System.Linq.Expressions.csproj b/src/libraries/System.Linq.Expressions/ref/System.Linq.Expressions.csproj
index 024288147d0b8..8ce6d5b73701a 100644
--- a/src/libraries/System.Linq.Expressions/ref/System.Linq.Expressions.csproj
+++ b/src/libraries/System.Linq.Expressions/ref/System.Linq.Expressions.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <NoWarn>$(NoWarn);CS0618</NoWarn>
     <Nullable>enable</Nullable>
   </PropertyGroup>
diff --git a/src/libraries/System.Linq.Expressions/src/System.Linq.Expressions.csproj b/src/libraries/System.Linq.Expressions/src/System.Linq.Expressions.csproj
index dce8fedbf2ac8..fba337b000b6e 100644
--- a/src/libraries/System.Linq.Expressions/src/System.Linq.Expressions.csproj
+++ b/src/libraries/System.Linq.Expressions/src/System.Linq.Expressions.csproj
@@ -3,16 +3,19 @@
     <TargetFrameworks>$(NetCoreAppCurrent);$(NetCoreAppCurrent)-iOS;$(NetCoreAppCurrent)-tvOS;$(NetCoreAppCurrent)-MacCatalyst</TargetFrameworks>
     <Nullable>enable</Nullable>
     <IsInterpreting>false</IsInterpreting>
-    <IsInterpreting Condition="'$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true' or '$(TargetsMacCatalyst)' == 'true'">true</IsInterpreting>
-    <ILLinkSubstitutionsLibraryBuildXml Condition="'$(IsInterpreting)' == 'true'">ILLink\ILLink.Substitutions.IsInterpreting.LibraryBuild.xml</ILLinkSubstitutionsLibraryBuildXml>
     <DefineConstants> $(DefineConstants);FEATURE_FAST_CREATE</DefineConstants>
-
+  </PropertyGroup>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
+  <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <IsInterpreting Condition="'$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'tvOS' or '$(TargetPlatformIdentifier)' == 'MacCatalyst'">true</IsInterpreting>
+    <ILLinkSubstitutionsLibraryBuildXml Condition="'$(IsInterpreting)' == 'true'">ILLink\ILLink.Substitutions.IsInterpreting.LibraryBuild.xml</ILLinkSubstitutionsLibraryBuildXml>
     <!--
       Disable constant propagation so that methods referenced from ILLink.Substitutions.xml don't get inlined
       with a wrong value at library build time and the substitution can still be selected at publish time.
       For iOS/tvOS/Catalyst we prefer smaller size by default, so keep constprop enabled to get rid of the expression compiler.
     -->
-    <ILLinkDisableIPConstProp Condition="'$(TargetsiOS)' != 'true' and '$(TargetstvOS)' != 'true' and '$(TargetsMacCatalyst)' != 'true'">true</ILLinkDisableIPConstProp>
+    <ILLinkDisableIPConstProp Condition="'$(TargetPlatformIdentifier)' != 'iOS' and '$(TargetPlatformIdentifier)' != 'tvOS' and '$(TargetPlatformIdentifier)' != 'MacCatalyst'">true</ILLinkDisableIPConstProp>
   </PropertyGroup>
   <ItemGroup>
     <ILLinkSubstitutionsXmls Include="$(ILLinkDirectory)ILLink.Substitutions.xml" />
diff --git a/src/libraries/System.Linq.Parallel/ref/System.Linq.Parallel.csproj b/src/libraries/System.Linq.Parallel/ref/System.Linq.Parallel.csproj
index 02094314ac02e..7f0337a585cf8 100644
--- a/src/libraries/System.Linq.Parallel/ref/System.Linq.Parallel.csproj
+++ b/src/libraries/System.Linq.Parallel/ref/System.Linq.Parallel.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Linq.Parallel/src/System.Linq.Parallel.csproj b/src/libraries/System.Linq.Parallel/src/System.Linq.Parallel.csproj
index b78dd81e422a9..5d2db8f850ac0 100644
--- a/src/libraries/System.Linq.Parallel/src/System.Linq.Parallel.csproj
+++ b/src/libraries/System.Linq.Parallel/src/System.Linq.Parallel.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
 	<Nullable>enable</Nullable>
   </PropertyGroup>
   <!-- Compiled Source Files -->
diff --git a/src/libraries/System.Linq.Queryable/ref/System.Linq.Queryable.csproj b/src/libraries/System.Linq.Queryable/ref/System.Linq.Queryable.csproj
index dc7cc09400acf..ef12af1519ae1 100644
--- a/src/libraries/System.Linq.Queryable/ref/System.Linq.Queryable.csproj
+++ b/src/libraries/System.Linq.Queryable/ref/System.Linq.Queryable.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Linq.Queryable/src/System.Linq.Queryable.csproj b/src/libraries/System.Linq.Queryable/src/System.Linq.Queryable.csproj
index d3def1d1063a4..0df3e5cb4780d 100644
--- a/src/libraries/System.Linq.Queryable/src/System.Linq.Queryable.csproj
+++ b/src/libraries/System.Linq.Queryable/src/System.Linq.Queryable.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Linq/ref/System.Linq.csproj b/src/libraries/System.Linq/ref/System.Linq.csproj
index f2c0fd1178a7b..476d2cbc4f0f4 100644
--- a/src/libraries/System.Linq/ref/System.Linq.csproj
+++ b/src/libraries/System.Linq/ref/System.Linq.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Linq/src/System.Linq.csproj b/src/libraries/System.Linq/src/System.Linq.csproj
index 4126dfb64148c..508041619b3d4 100644
--- a/src/libraries/System.Linq/src/System.Linq.csproj
+++ b/src/libraries/System.Linq/src/System.Linq.csproj
@@ -2,7 +2,11 @@
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent);$(NetCoreAppCurrent)-Browser;$(NetCoreAppCurrent)-Android;$(NetCoreAppCurrent)-iOS;$(NetCoreAppCurrent)-tvOS</TargetFrameworks>
     <Nullable>enable</Nullable>
-    <OptimizeForSize Condition="'$(TargetsBrowser)' == 'true' or '$(TargetsAndroid)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true'">true</OptimizeForSize>
+  </PropertyGroup>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
+  <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <OptimizeForSize Condition="'$(TargetPlatformIdentifier)' == 'Browser' or '$(TargetPlatformIdentifier)' == 'Android' or '$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'tvOS'">true</OptimizeForSize>
   </PropertyGroup>
   <ItemGroup Condition="'$(OptimizeForSize)' == true">
     <Compile Include="System\Linq\Enumerable.SizeOpt.cs" />
diff --git a/src/libraries/System.Management/src/System.Management.csproj b/src/libraries/System.Management/src/System.Management.csproj
index e64ebcf61db51..7f530935c20b4 100644
--- a/src/libraries/System.Management/src/System.Management.csproj
+++ b/src/libraries/System.Management/src/System.Management.csproj
@@ -20,9 +20,10 @@ System.Management.SelectQuery</PackageDescription>
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsWindows)' != 'true'">SR.PlatformNotSupported_SystemManagement</GeneratePlatformNotSupportedAssemblyMessage>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' != 'windows'">SR.PlatformNotSupported_SystemManagement</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
              Link="Common\Interop\Windows\Interop.Libraries.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.FreeLibrary.cs"
diff --git a/src/libraries/System.Memory/ref/System.Memory.csproj b/src/libraries/System.Memory/ref/System.Memory.csproj
index 85853190888b8..a1511feb8809f 100644
--- a/src/libraries/System.Memory/ref/System.Memory.csproj
+++ b/src/libraries/System.Memory/ref/System.Memory.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Memory/src/System.Memory.csproj b/src/libraries/System.Memory/src/System.Memory.csproj
index b9f9e1e818f11..f11858f7e2f87 100644
--- a/src/libraries/System.Memory/src/System.Memory.csproj
+++ b/src/libraries/System.Memory/src/System.Memory.csproj
@@ -3,7 +3,7 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
     <Nullable>enable</Nullable>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <!-- ArrayBufferWriter is publicly exposed from the System.Memory ref and only it should define this constant as true.  -->
     <DefineConstants>$(DefineConstants);MAKE_ABW_PUBLIC</DefineConstants>
   </PropertyGroup>
diff --git a/src/libraries/System.Net.Http.WinHttpHandler/src/System.Net.Http.WinHttpHandler.csproj b/src/libraries/System.Net.Http.WinHttpHandler/src/System.Net.Http.WinHttpHandler.csproj
index 41d016898b1a2..e1aa13b7c867c 100644
--- a/src/libraries/System.Net.Http.WinHttpHandler/src/System.Net.Http.WinHttpHandler.csproj
+++ b/src/libraries/System.Net.Http.WinHttpHandler/src/System.Net.Http.WinHttpHandler.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IncludeDllSafeSearchPathAttribute>true</IncludeDllSafeSearchPathAttribute>
-    <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent);$(NetCoreAppMinimum)-windows;$(NetCoreAppMinimum);netstandard2.1;netstandard2.0;$(NetFrameworkMinimum)</TargetFrameworks>
+    <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent);$(NetCoreAppMinimum)-windows;$(NetCoreAppMinimum);netstandard2.0;$(NetFrameworkMinimum)</TargetFrameworks>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <Nullable>enable</Nullable>
     <IsPackable>true</IsPackable>
@@ -13,11 +13,11 @@ System.Net.Http.WinHttpHandler</PackageDescription>
 
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) != '.NETFramework' and
-                                                            '$(TargetsWindows)' != 'true'">SR.PlatformNotSupported_WinHttpHandler</GeneratePlatformNotSupportedAssemblyMessage>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) != '.NETFramework' and '$(TargetPlatformIdentifier)' != 'windows'">SR.PlatformNotSupported_WinHttpHandler</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
 
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true' or '$(TargetFrameworkIdentifier)' == '.NETFramework'">
+  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework' or '$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)\Interop\Windows\Interop.Libraries.cs"
              Link="Common\Interop\Windows\Interop.Libraries.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Crypt32\Interop.CERT_CONTEXT.cs"
@@ -108,7 +108,7 @@ System.Net.Http.WinHttpHandler</PackageDescription>
              Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'" />
   </ItemGroup>
 
-  <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0')) and '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0-windows'))">
     <Compile Include="$(CommonPath)DisableRuntimeMarshalling.cs"
              Link="Common\DisableRuntimeMarshalling.cs" />
   </ItemGroup>
@@ -135,7 +135,7 @@ System.Net.Http.WinHttpHandler</PackageDescription>
     <Reference Include="System.Security.Cryptography" />
   </ItemGroup>
 
-  <ItemGroup Condition="!$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'netstandard2.1'))">
+  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'">
     <PackageReference Include="System.Buffers" Version="$(SystemBuffersVersion)" />
     <PackageReference Include="System.Memory" Version="$(SystemMemoryVersion)" />
     <!-- S.R.C.Unsafe isn't a primary but transitive dependency and this P2P makes sure that the live version is used. -->
diff --git a/src/libraries/System.Net.Http.WinHttpHandler/tests/UnitTests/System.Net.Http.WinHttpHandler.Unit.Tests.csproj b/src/libraries/System.Net.Http.WinHttpHandler/tests/UnitTests/System.Net.Http.WinHttpHandler.Unit.Tests.csproj
index 381230d2a9bc3..e9d68fbff06ef 100644
--- a/src/libraries/System.Net.Http.WinHttpHandler/tests/UnitTests/System.Net.Http.WinHttpHandler.Unit.Tests.csproj
+++ b/src/libraries/System.Net.Http.WinHttpHandler/tests/UnitTests/System.Net.Http.WinHttpHandler.Unit.Tests.csproj
@@ -11,7 +11,7 @@
   <ItemGroup>
     <DefaultReferenceExclusion Include="System.Net.Http.WinHttpHandler" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsWindows)' == 'true' ">
+  <ItemGroup>
     <Compile Include="$(CommonTestPath)System\Net\SslProtocolSupport.cs"
              Link="CommonTest\System\Net\SslProtocolSupport.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
diff --git a/src/libraries/System.Net.Http/ref/System.Net.Http.csproj b/src/libraries/System.Net.Http/ref/System.Net.Http.csproj
index 1b20e03c7905a..beb13cf450058 100644
--- a/src/libraries/System.Net.Http/ref/System.Net.Http.csproj
+++ b/src/libraries/System.Net.Http/ref/System.Net.Http.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Net.Http/src/System.Net.Http.csproj b/src/libraries/System.Net.Http/src/System.Net.Http.csproj
index 0792ba26c0551..41a0065fa038d 100644
--- a/src/libraries/System.Net.Http/src/System.Net.Http.csproj
+++ b/src/libraries/System.Net.Http/src/System.Net.Http.csproj
@@ -6,41 +6,26 @@
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Linux;$(NetCoreAppCurrent)-OSX;$(NetCoreAppCurrent)-FreeBSD;$(NetCoreAppCurrent)-MacCatalyst;$(NetCoreAppCurrent)-iOS;$(NetCoreAppCurrent)-tvOS;$(NetCoreAppCurrent)-Browser;$(NetCoreAppCurrent)-illumos;$(NetCoreAppCurrent)-Solaris;$(NetCoreAppCurrent)-Android;$(NetCoreAppCurrent)</TargetFrameworks>
     <Nullable>enable</Nullable>
   </PropertyGroup>
-  <PropertyGroup Condition=" '$(TargetsOSX)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true' or '$(TargetsMacCatalyst)' == 'true'">
-    <DefineConstants>$(DefineConstants);SYSNETHTTP_NO_OPENSSL</DefineConstants>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(TargetsAndroid)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetsMacCatalyst)' == 'true' or '$(TargetsTVOS)' == 'true'">
-    <DefineConstants>$(DefineConstants);TARGET_MOBILE</DefineConstants>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(TargetsAndroid)' == 'true'">
-    <DefineConstants>$(DefineConstants);TARGET_ANDROID</DefineConstants>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(TargetsiOS)' == 'true'">
-    <DefineConstants>$(DefineConstants);TARGET_IOS</DefineConstants>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(TargetsMacCatalyst)' == 'true'">
-    <DefineConstants>$(DefineConstants);TARGET_MACCATALYST</DefineConstants>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(TargetsTVOS)' == 'true'">
-    <DefineConstants>$(DefineConstants);TARGET_TVOS</DefineConstants>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(TargetsBrowser)' == 'true'">
-    <DefineConstants>$(DefineConstants);TARGET_BROWSER</DefineConstants>
-  </PropertyGroup>
-  <!-- ILLinker settings -->
-  <PropertyGroup>
-    <ILLinkDirectory>$(MSBuildThisFileDirectory)ILLink\</ILLinkDirectory>
-  </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
     <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
     <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == ''">SR.PlatformNotSupported_NetHttp</GeneratePlatformNotSupportedAssemblyMessage>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'OSX' or '$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'tvOS' or '$(TargetPlatformIdentifier)' == 'MacCatalyst'">$(DefineConstants);SYSNETHTTP_NO_OPENSSL</DefineConstants>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'Android' or '$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'MacCatalyst' or '$(TargetPlatformIdentifier)' == 'tvOS'">$(DefineConstants);TARGET_MOBILE</DefineConstants>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'Android'">$(DefineConstants);TARGET_ANDROID</DefineConstants>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'iOS'">$(DefineConstants);TARGET_IOS</DefineConstants>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'MacCatalyst'">$(DefineConstants);TARGET_MACCATALYST</DefineConstants>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'tvOS'">$(DefineConstants);TARGET_TVOS</DefineConstants>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'Browser'">$(DefineConstants);TARGET_BROWSER</DefineConstants>
+    <!-- ILLinker settings -->
+    <ILLinkDirectory>$(MSBuildThisFileDirectory)ILLink\</ILLinkDirectory>
   </PropertyGroup>
   <ItemGroup>
     <ILLinkSubstitutionsXmls Include="$(ILLinkDirectory)ILLink.Substitutions.xml" />
-    <ILLinkSubstitutionsXmls Condition="'$(TargetsAndroid)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetsMacCatalyst)' == 'true' or '$(TargetsTVOS)' == 'true'"
-                             Include="$(ILLinkDirectory)ILLink.Substitutions.mobile.xml" />
-    <ILLinkSuppressionsXmls Condition="'$(TargetsMobile)' == 'true'" Include="$(ILLinkDirectory)ILLink.Suppressions.Mobile.LibraryBuild.xml" />
+  </ItemGroup>
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Android' or '$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'MacCatalyst' or '$(TargetPlatformIdentifier)' == 'tvOS' or '$(TargetPlatformIdentifier)' == 'Browser'">
+    <ILLinkSubstitutionsXmls Include="$(ILLinkDirectory)ILLink.Substitutions.mobile.xml" Condition="'$(TargetPlatformIdentifier)' != 'Browser'" />
+    <ILLinkSuppressionsXmls Include="$(ILLinkDirectory)ILLink.Suppressions.Mobile.LibraryBuild.xml" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="System\Net\Http\ByteArrayContent.cs" />
@@ -60,11 +45,11 @@
     <Compile Include="System\Net\Http\Headers\KnownHeaders.cs" />
     <Compile Include="System\Net\Http\HttpBaseStream.cs" />
     <Compile Include="System\Net\Http\HttpClient.cs" />
-    <Compile Condition="'$(TargetsAndroid)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetsMacCatalyst)' == 'true' or '$(TargetsTVOS)' == 'true'"
+    <Compile Condition="'$(TargetPlatformIdentifier)' == 'Android' or '$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'MacCatalyst' or '$(TargetPlatformIdentifier)' == 'tvOS'"
              Include="System\Net\Http\HttpClientHandler.AnyMobile.cs" />
-    <Compile Condition="'$(TargetsAndroid)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetsMacCatalyst)' == 'true' or '$(TargetsTVOS)' == 'true'"
+    <Compile Condition="'$(TargetPlatformIdentifier)' == 'Android' or '$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'MacCatalyst' or '$(TargetPlatformIdentifier)' == 'tvOS'"
              Include="System\Net\Http\HttpClientHandler.AnyMobile.InvokeNativeHandler.cs" />
-    <Compile Condition="'$(TargetsAndroid)' != 'true' and '$(TargetsiOS)' != 'true' and '$(TargetsMacCatalyst)' != 'true' and '$(TargetsTVOS)' != 'true'"
+    <Compile Condition="'$(TargetPlatformIdentifier)' != 'Android' and '$(TargetPlatformIdentifier)' != 'iOS' and '$(TargetPlatformIdentifier)' != 'MacCatalyst' and '$(TargetPlatformIdentifier)' != 'tvOS'"
              Include="System\Net\Http\HttpClientHandler.cs" />
     <Compile Include="System\Net\Http\HttpCompletionOption.cs" />
     <Compile Include="System\Net\Http\HttpContent.cs" />
@@ -165,7 +150,7 @@
              Link="Common\System\Net\Http\aspnetcore\Http3\QPack\H3StaticTable.cs" />
   </ItemGroup>
   <!-- SocketsHttpHandler implementation -->
-  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetsBrowser)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'Browser'">
     <Compile Include="System\Net\Http\HttpHandlerDefaults.cs" />
     <Compile Include="System\Net\Http\HttpMethod.Http3.cs" />
     <Compile Include="System\Net\Http\Headers\AltSvcHeaderParser.cs" />
@@ -173,7 +158,7 @@
     <Compile Include="System\Net\Http\Headers\KnownHeader.Http2And3.cs" />
     <Compile Include="System\Net\Http\SocketsHttpHandler\AuthenticationHelper.cs" />
     <Compile Include="System\Net\Http\SocketsHttpHandler\AuthenticationHelper.Digest.cs" />
-    <Compile Condition="'$(TargetstvOS)' != 'true'" Include="System\Net\Http\SocketsHttpHandler\AuthenticationHelper.NtAuth.cs" />
+    <Compile Condition="'$(TargetPlatformIdentifier)' != 'tvOS'" Include="System\Net\Http\SocketsHttpHandler\AuthenticationHelper.NtAuth.cs" />
     <Compile Include="System\Net\Http\SocketsHttpHandler\ChunkedEncodingReadStream.cs" />
     <Compile Include="System\Net\Http\SocketsHttpHandler\ChunkedEncodingWriteStream.cs" />
     <Compile Include="System\Net\Http\SocketsHttpHandler\ConnectHelper.cs" />
@@ -222,7 +207,7 @@
     <Compile Include="System\Net\Http\SocketsHttpHandler\SystemProxyInfo.cs" />
     <Compile Include="System\Net\Http\SocketsHttpHandler\SocksHelper.cs" />
     <Compile Include="System\Net\Http\SocketsHttpHandler\SocksException.cs" />
-    <Compile Condition="'$(TargetstvOS)' != 'true'" Include="$(CommonPath)System\Net\NTAuthentication.Common.cs"
+    <Compile Condition="'$(TargetPlatformIdentifier)' != 'tvOS'" Include="$(CommonPath)System\Net\NTAuthentication.Common.cs"
              Link="Common\System\Net\NTAuthentication.Common.cs" />
     <Compile Include="$(CommonPath)System\Net\ContextFlagsPal.cs"
              Link="Common\System\Net\ContextFlagsPal.cs" />
@@ -332,17 +317,17 @@
     </Compile>
   </ItemGroup>
   <!-- Linux specific files -->
-  <ItemGroup Condition="'$(TargetsLinux)' == 'true' or '$(TargetsBrowser)' == 'true' ">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Linux' or '$(TargetPlatformIdentifier)' == 'Android' or '$(TargetPlatformIdentifier)' == 'Browser' ">
     <Compile Include="$(CommonPath)Interop\Linux\Interop.Libraries.cs"
              Link="Common\Interop\Linux\Interop.Libraries.cs" />
   </ItemGroup>
   <!-- FreeBSD specific files -->
-  <ItemGroup Condition="'$(TargetsFreeBSD)' == 'true' ">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'FreeBSD' ">
     <Compile Include="$(CommonPath)Interop\FreeBSD\Interop.Libraries.cs"
              Link="Common\Interop\FreeBSD\Interop.Libraries.cs" />
   </ItemGroup>
   <!-- SocketsHttpHandler platform parts -->
-  <ItemGroup Condition=" '$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows' and '$(TargetPlatformIdentifier)' != 'Browser'">
     <Compile Include="System\Net\Http\SocketsHttpHandler\HttpEnvironmentProxy.cs" />
     <Compile Include="System\Net\Http\SocketsHttpHandler\HttpEnvironmentProxy.Unix.cs" />
     <Compile Include="System\Net\Http\SocketsHttpHandler\CurrentUserIdentityProvider.Unix.cs" />
@@ -361,7 +346,7 @@
     <Compile Include="$(CommonPath)Interop\Unix\System.Net.Security.Native\Interop.NetSecurityNative.IsNtlmInstalled.cs"
              Link="Common\Interop\Unix\System.Net.Security.Native\Interop.NetSecurityNative.IsNtlmInstalled.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' and '$(TargetstvOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows' and '$(TargetPlatformIdentifier)' != 'Browser' and '$(TargetPlatformIdentifier)' != 'tvOS'">
     <Compile Include="$(CommonPath)Interop\Unix\System.Net.Security.Native\Interop.GssApiException.cs"
              Link="Common\Interop\Unix\System.Net.Security.Native\Interop.GssApiException.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\System.Net.Security.Native\Interop.GssBuffer.cs"
@@ -377,18 +362,18 @@
     <Compile Include="$(CommonPath)System\Net\Security\NegotiateStreamPal.Unix.cs"
              Link="Common\System\Net\Security\NegotiateStreamPal.Unix.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetstvOS)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'tvOS'">
     <Compile Include="System\Net\Http\SocketsHttpHandler\AuthenticationHelper.NtAuth.tvOS.cs" />
     <Compile Include="$(CommonPath)Microsoft\Win32\SafeHandles\GssSafeHandles.PlatformNotSupported.cs"
              Link="Common\Microsoft\Win32\SafeHandles\GssSafeHandles.PlatformNotSupported.cs" />
     <Compile Include="$(CommonPath)System\Net\Security\NegotiateStreamPal.PlatformNotSupported.cs"
              Link="Common\System\Net\Security\NegotiateStreamPal.PlatformNotSupported.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' and '$(TargetsOSX)' != 'true' and '$(TargetsiOS)' != 'true' and '$(TargetstvOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows' and '$(TargetPlatformIdentifier)' != 'Browser' and '$(TargetPlatformIdentifier)' != 'OSX' and '$(TargetPlatformIdentifier)' != 'iOS' and '$(TargetPlatformIdentifier)' != 'tvOS'">
     <Compile Include="System\Net\Http\SocketsHttpHandler\HttpNoProxy.cs" />
     <Compile Include="System\Net\Http\SocketsHttpHandler\SystemProxyInfo.Unix.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsOSX)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'OSX' or '$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'tvOS'">
     <Compile Include="System\Net\Http\SocketsHttpHandler\SystemProxyInfo.OSX.cs" />
     <Compile Include="System\Net\Http\SocketsHttpHandler\MacProxy.cs" />
     <Compile Include="$(CommonPath)Interop\OSX\Interop.CoreFoundation.cs"
@@ -416,7 +401,7 @@
     <Compile Include="$(CommonPath)Microsoft\Win32\SafeHandles\SafeCreateHandle.OSX.cs"
              Link="Common\Microsoft\Win32\SafeHandles\SafeCreateHandle.OSX.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)\System\Net\HttpStatusDescription.cs"
              Link="Common\System\Net\HttpStatusDescription.cs" />
     <Compile Include="System\Net\Http\SocketsHttpHandler\SystemProxyInfo.Windows.cs" />
@@ -532,7 +517,7 @@
     <Compile Include="$(CommonPath)Interop\Windows\SspiCli\SSPIWrapper.cs"
              Link="Common\Interop\Windows\SspiCli\SSPIWrapper.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows' and '$(TargetPlatformIdentifier)' != 'Browser'">
     <Compile Include="$(CommonPath)System\StrongToWeakReference.cs"
              Link="Common\Interop\Unix\StrongToWeakReference.cs" />
     <Compile Include="$(CommonPath)System\Net\SecurityProtocol.cs"
@@ -582,7 +567,7 @@
     <Compile Include="$(CommonPath)System\Threading\Tasks\TaskToApm.cs"
              Link="Common\System\Threading\Tasks\TaskToApm.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' and '$(TargetsOSX)' != 'true' and '$(TargetsiOS)' != 'true' and '$(TargetstvOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows' and '$(TargetPlatformIdentifier)' != 'Browser' and '$(TargetPlatformIdentifier)' != 'OSX' and '$(TargetPlatformIdentifier)' != 'iOS' and '$(TargetPlatformIdentifier)' != 'tvOS'">
     <Compile Include="$(CommonPath)Interop\Unix\System.Security.Cryptography.Native\Interop.ASN1.cs"
              Link="Common\Interop\Unix\System.Security.Cryptography.Native\Interop.ASN1.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\System.Security.Cryptography.Native\Interop.BIO.cs"
@@ -630,7 +615,7 @@
     <Compile Include="$(CommonPath)System\Net\Security\CertificateValidation.Unix.cs"
              Link="Common\System\Net\Security\CertificateValidation.Unix.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="$(CommonPath)\System\StringExtensions.cs"
              Link="Common\System\StringExtensions.cs" />
     <Compile Include="$(CommonPath)\System\Net\HttpStatusDescription.cs"
@@ -669,27 +654,27 @@
     <Reference Include="System.Runtime.Extensions" />
     <Reference Include="System.Runtime.CompilerServices.Unsafe" />
     <Reference Include="System.Runtime.InteropServices" />
-    <Reference Include="System.Security.Claims" Condition="'$(TargetsWindows)' == 'true'" />
+    <Reference Include="System.Security.Claims" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Reference Include="System.Security.Cryptography" />
     <Reference Include="System.Security.Cryptography.Algorithms" />
     <Reference Include="System.Security.Cryptography.Csp" />
     <Reference Include="System.Security.Cryptography.Encoding" />
     <Reference Include="System.Security.Cryptography.OpenSsl" />
     <Reference Include="System.Security.Cryptography.X509Certificates" />
-    <Reference Include="System.Security.Principal" Condition="'$(TargetsWindows)' == 'true'" />
+    <Reference Include="System.Security.Principal" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Reference Include="System.Security.Principal.Windows" />
     <Reference Include="System.Threading" />
     <Reference Include="System.Threading.Channels" />
     <Reference Include="System.IO.Compression.Brotli" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows' and '$(TargetPlatformIdentifier)' != 'Browser'">
     <Reference Include="System.Diagnostics.StackTrace" />
     <Reference Include="System.IO.FileSystem" />
     <Reference Include="System.Security.Cryptography.Algorithms" />
     <Reference Include="System.Security.Cryptography.Encoding" />
     <Reference Include="System.Security.Cryptography" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Browser'">
     <ProjectReference Include="$(LibrariesProjectRoot)System.Private.Runtime.InteropServices.JavaScript\src\System.Private.Runtime.InteropServices.JavaScript.csproj" />
   </ItemGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Net.Http/tests/FunctionalTests/System.Net.Http.Functional.Tests.csproj b/src/libraries/System.Net.Http/tests/FunctionalTests/System.Net.Http.Functional.Tests.csproj
index 1b4a5aa376923..f8d30de1f7b0d 100644
--- a/src/libraries/System.Net.Http/tests/FunctionalTests/System.Net.Http.Functional.Tests.csproj
+++ b/src/libraries/System.Net.Http/tests/FunctionalTests/System.Net.Http.Functional.Tests.csproj
@@ -1,8 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <StringResourcesPath>../../src/Resources/Strings.resx</StringResourcesPath>
-    <DefineConstants Condition="'$(TargetsWindows)'=='true'">$(DefineConstants);TargetsWindows</DefineConstants>
-    <DefineConstants Condition="'$(TargetsBrowser)'=='true'">$(DefineConstants);TARGETS_BROWSER</DefineConstants>
     <DefineConstants>$(DefineConstants);SYSNETHTTP_NO_OPENSSL;HTTP3</DefineConstants>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <IncludeRemoteExecutor>true</IncludeRemoteExecutor>
@@ -10,6 +8,13 @@
     <EnableDllImportGenerator>true</EnableDllImportGenerator>
   </PropertyGroup>
 
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
+  <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'windows'">$(DefineConstants);TargetsWindows</DefineConstants>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'Browser'">$(DefineConstants);TARGETS_BROWSER</DefineConstants>
+  </PropertyGroup>
+
   <ItemGroup>
     <RuntimeHostConfigurationOption Include="System.Net.SocketsHttpHandler.Http3Support" Value="true" />
   </ItemGroup>
@@ -34,13 +39,13 @@
   <ItemGroup>
     <Compile Include="$(CommonPath)DisableRuntimeMarshalling.cs"
              Link="Common\DisableRuntimeMarshalling.cs" />
-    <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs" Condition="'$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true'"
+    <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs" Condition="'$(TargetPlatformIdentifier)' != 'windows'"
              Link="Common\Interop\Unix\Interop.Libraries.cs" />
     <Compile Include="$(CommonPath)System\Net\Logging\NetEventSource.Common.cs"
              Link="Common\System\Net\Logging\NetEventSource.Common.cs" />
     <Compile Include="$(CommonPath)System\Threading\Tasks\TaskToApm.cs"
              Link="System\System\Threading\Tasks\TaskToApm.cs" />
-    <Compile Include="$(CommonPath)Interop\Unix\System.Net.Security.Native\Interop.NetSecurityNative.IsNtlmInstalled.cs" Condition="'$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true'"
+    <Compile Include="$(CommonPath)Interop\Unix\System.Net.Security.Native\Interop.NetSecurityNative.IsNtlmInstalled.cs" Condition="'$(TargetPlatformIdentifier)' != 'windows'"
              Link="Common\Interop\Unix\System.Net.Security.Native\Interop.NetSecurityNative.IsNtlmInstalled.cs" />
     <Compile Include="$(CommonTestPath)System\Buffers\NativeMemoryManager.cs"
              Link="Common\System\Buffers\NativeMemoryManager.cs" />
@@ -68,9 +73,9 @@
              Link="Common\System\Net\HttpsTestServer.cs" />
     <Compile Include="$(CommonTestPath)System\Net\Capability.Security.cs"
              Link="Common\System\Net\Capability.Security.cs" />
-    <Compile Include="$(CommonTestPath)System\Net\Capability.Security.Windows.cs" Condition="'$(TargetsWindows)' == 'true'"
+    <Compile Include="$(CommonTestPath)System\Net\Capability.Security.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'"
              Link="Common\System\Net\Capability.Security.Windows.cs" />
-    <Compile Include="$(CommonTestPath)System\Net\Capability.Security.Unix.cs" Condition="'$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true'"
+    <Compile Include="$(CommonTestPath)System\Net\Capability.Security.Unix.cs" Condition="'$(TargetPlatformIdentifier)' != 'windows'"
              Link="Common\System\Net\Capability.Security.Unix.cs" />
     <Compile Include="$(CommonTestPath)System\Net\Configuration.cs"
              Link="Common\System\Net\Configuration.cs" />
@@ -162,7 +167,7 @@
     <Compile Include="HttpClientHandlerTestBase.SocketsHttpHandler.cs" />
     <Compile Include="DiagnosticsTests.cs" />
     <Compile Include="HttpClientTest.cs" />
-    <Compile Include="$(CommonTestPath)System\Net\Http\HttpClientEKUTest.cs" Condition="'$(TargetsBrowser)' != 'true'"
+    <Compile Include="$(CommonTestPath)System\Net\Http\HttpClientEKUTest.cs" Condition="'$(TargetPlatformIdentifier)' != 'Browser'"
              Link="Common\System\Net\Http\HttpClientEKUTest.cs" />
     <Compile Include="$(CommonTestPath)System\Net\Http\HttpClient.SelectedSitesTest.cs"
              Link="Common\System\Net\Http\HttpClient.SelectedSitesTest.cs" />
@@ -209,7 +214,7 @@
              Link="ProductionCode\Common\System\Net\StreamBuffer.cs" />
   </ItemGroup>
   <!-- Windows specific files -->
-  <ItemGroup Condition=" '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition=" '$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
              Link="Common\Interop\Windows\Interop.Libraries.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.UNICODE_STRING.cs"
@@ -316,12 +321,12 @@
     <Compile Include="ImpersonatedAuthTests.cs" />
   </ItemGroup>
   <!-- Linux specific files -->
-  <ItemGroup Condition="'$(TargetsLinux)' == 'true' or '$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Linux' or '$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="$(CommonPath)Interop\Linux\Interop.Libraries.cs"
              Link="Common\Interop\Linux\Interop.Libraries.cs" />
   </ItemGroup>
   <!-- OSX specific files -->
-  <ItemGroup Condition=" '$(TargetsOSX)' == 'true' ">
+  <ItemGroup Condition=" '$(TargetPlatformIdentifier)' == 'OSX' ">
     <Compile Include="$(CommonPath)Interop\OSX\Interop.Libraries.cs"
              Link="Common\Interop\OSX\Interop.Libraries.cs" />
   </ItemGroup>
diff --git a/src/libraries/System.Net.Http/tests/UnitTests/System.Net.Http.Unit.Tests.csproj b/src/libraries/System.Net.Http/tests/UnitTests/System.Net.Http.Unit.Tests.csproj
index f676e0381bd1f..0ad988c4e5415 100644
--- a/src/libraries/System.Net.Http/tests/UnitTests/System.Net.Http.Unit.Tests.csproj
+++ b/src/libraries/System.Net.Http/tests/UnitTests/System.Net.Http.Unit.Tests.csproj
@@ -233,26 +233,26 @@
              Link="ProductionCode\System\Net\Http\SocketsHttpHandler\RuntimeSettingParser.cs" />
     <Compile Include="..\..\src\System\Net\Http\SocketsHttpHandler\HttpEnvironmentProxy.cs"
              Link="ProductionCode\System\Net\Http\SocketsHttpHandler\HttpEnvironmentProxy.cs" />
-    <Compile Include="..\..\src\System\Net\Http\SocketsHttpHandler\HttpEnvironmentProxy.Unix.cs" Condition="('$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true') and $([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', '$(NetCoreAppCurrent)'))"
+    <Compile Include="..\..\src\System\Net\Http\SocketsHttpHandler\HttpEnvironmentProxy.Unix.cs" Condition="'$(TargetPlatformIdentifier)' != 'windows'"
              Link="ProductionCode\System\Net\Http\SocketsHttpHandler\HttpEnvironmentProxy.Unix.cs" />
-    <Compile Include="..\..\src\System\Net\Http\SocketsHttpHandler\HttpEnvironmentProxy.Windows.cs" Condition=" '$(TargetsWindows)' == 'true' and $([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', '$(NetCoreAppCurrent)'))"
+    <Compile Include="..\..\src\System\Net\Http\SocketsHttpHandler\HttpEnvironmentProxy.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'"
              Link="ProductionCode\System\Net\Http\SocketsHttpHandler\HttpEnvironmentProxy.Windows.cs" />
     <Compile Include="..\..\src\System\Net\Http\SocketsHttpHandler\HttpUtilities.cs"
              Link="ProductionCode\System\Net\Http\SocketsHttpHandler\HttpUtilities.cs" />
     <Compile Include="..\..\src\System\Net\Http\SocketsHttpHandler\SystemProxyInfo.cs"
              Link="ProductionCode\System\Net\Http\SocketsHttpHandler\SystemProxyInfo.cs" />
-    <Compile Include="..\..\src\System\Net\Http\SocketsHttpHandler\SystemProxyInfo.OSX.cs" Condition=" ('$(TargetsOSX)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true') and $([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', '$(NetCoreAppCurrent)'))"
+    <Compile Include="..\..\src\System\Net\Http\SocketsHttpHandler\SystemProxyInfo.OSX.cs" Condition=" '$(TargetPlatformIdentifier)' == 'OSX' or '$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'tvOS'"
              Link="ProductionCode\System\Net\Http\SocketsHttpHandler\SystemProxyInfo.OSX.cs" />
-    <Compile Include="..\..\src\System\Net\Http\SocketsHttpHandler\SystemProxyInfo.Unix.cs" Condition="('$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true') and '$(TargetsOSX)' != 'true' and '$(TargetsiOS)' != 'true' and '$(TargetstvOS)' != 'true' and $([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', '$(NetCoreAppCurrent)'))"
+    <Compile Include="..\..\src\System\Net\Http\SocketsHttpHandler\SystemProxyInfo.Unix.cs" Condition="'$(TargetPlatformIdentifier)' != 'windows' and '$(TargetPlatformIdentifier)' != 'OSX' and '$(TargetPlatformIdentifier)' != 'iOS' and '$(TargetPlatformIdentifier)' != 'tvOS'"
              Link="ProductionCode\System\Net\Http\SocketsHttpHandler\SystemProxyInfo.Unix.cs" />
-    <Compile Include="..\..\src\System\Net\Http\SocketsHttpHandler\SystemProxyInfo.Windows.cs" Condition=" '$(TargetsWindows)' == 'true' and $([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', '$(NetCoreAppCurrent)'))"
+    <Compile Include="..\..\src\System\Net\Http\SocketsHttpHandler\SystemProxyInfo.Windows.cs" Condition=" '$(TargetPlatformIdentifier)' == 'windows' "
              Link="ProductionCode\System\Net\Http\SocketsHttpHandler\SystemProxyInfo.Windows.cs" />
     <Compile Include="$(CommonPath)System\Net\Http\HttpHandlerDefaults.cs"
              Link="ProductionCode\System\Net\Http\HttpHandlerDefaults.cs" />
     <Compile Include="DigestAuthenticationTests.cs" />
     <Compile Include="Fakes\HttpClientHandler.cs" />
     <Compile Include="Fakes\HttpTelemetry.cs" />
-    <Compile Include="Fakes\MacProxy.cs" Condition=" ('$(TargetsOSX)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true') and $([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', '$(NetCoreAppCurrent)'))" />
+    <Compile Include="Fakes\MacProxy.cs" Condition="'$(TargetPlatformIdentifier)' == 'OSX' or '$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'tvOS'" />
     <Compile Include="Headers\AltSvcHeaderParserTest.cs" />
     <Compile Include="Headers\AuthenticationHeaderValueTest.cs" />
     <Compile Include="Headers\ByteArrayHeaderParserTest.cs" />
diff --git a/src/libraries/System.Net.HttpListener/ref/System.Net.HttpListener.csproj b/src/libraries/System.Net.HttpListener/ref/System.Net.HttpListener.csproj
index 00bc53369a021..470e002db2317 100644
--- a/src/libraries/System.Net.HttpListener/ref/System.Net.HttpListener.csproj
+++ b/src/libraries/System.Net.HttpListener/ref/System.Net.HttpListener.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Net.HttpListener/src/System.Net.HttpListener.csproj b/src/libraries/System.Net.HttpListener/src/System.Net.HttpListener.csproj
index 1da319175f0d2..f50c50e9eed6c 100644
--- a/src/libraries/System.Net.HttpListener/src/System.Net.HttpListener.csproj
+++ b/src/libraries/System.Net.HttpListener/src/System.Net.HttpListener.csproj
@@ -4,7 +4,11 @@
     <ForceManagedImplementation>false</ForceManagedImplementation>
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent)</TargetFrameworks>
     <Nullable>enable</Nullable>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsAnyOS)' == 'true'">SR.SystemNetHttpListener_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+  </PropertyGroup>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
+  <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == ''">SR.SystemNetHttpListener_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
   <ItemGroup>
     <ProjectReference Include="$(LibrariesProjectRoot)System.Security.Principal.Windows\src\System.Security.Principal.Windows.csproj" />
@@ -35,7 +39,7 @@
     <Reference Include="System.Threading" />
     <Reference Include="System.Threading.Overlapped" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="System\Net\BoundaryType.cs" />
     <Compile Include="System\Net\EntitySendFormat.cs" />
     <Compile Include="System\Net\HttpListenerPrefixCollection.cs" />
@@ -87,7 +91,7 @@
     <Compile Include="$(CommonPath)System\HexConverter.cs"
              Link="Common\System\HexConverter.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true' and '$(ForceManagedImplementation)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows' and '$(ForceManagedImplementation)' != 'true'">
     <Compile Include="System\Net\Windows\HttpListener.Windows.cs" />
     <Compile Include="System\Net\Windows\HttpListenerSession.Windows.cs" />
     <Compile Include="System\Net\Windows\HttpListenerContext.Windows.cs" />
@@ -251,7 +255,7 @@
     <Compile Include="$(CommonPath)Interop\Windows\SspiCli\SSPIWrapper.cs"
              Link="Common\Interop\Windows\SspiCli\SSPIWrapper.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' or '$(ForceManagedImplementation)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(ForceManagedImplementation)' == 'true'">
     <Compile Include="System\Net\Managed\HttpEndPointListener.cs" />
     <Compile Include="System\Net\Managed\HttpEndPointManager.cs" />
     <Compile Include="System\Net\Managed\HttpConnection.cs" />
diff --git a/src/libraries/System.Net.Mail/ref/System.Net.Mail.csproj b/src/libraries/System.Net.Mail/ref/System.Net.Mail.csproj
index 99ae2fb8049c9..119925b1b0e21 100644
--- a/src/libraries/System.Net.Mail/ref/System.Net.Mail.csproj
+++ b/src/libraries/System.Net.Mail/ref/System.Net.Mail.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Net.Mail/src/System.Net.Mail.csproj b/src/libraries/System.Net.Mail/src/System.Net.Mail.csproj
index c80216d012cb2..d73fe7a77ce48 100644
--- a/src/libraries/System.Net.Mail/src/System.Net.Mail.csproj
+++ b/src/libraries/System.Net.Mail/src/System.Net.Mail.csproj
@@ -3,12 +3,12 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent)-Browser;$(NetCoreAppCurrent)-tvOS;$(NetCoreAppCurrent)</TargetFrameworks>
     <Nullable>enable</Nullable>
-    <DefineConstants Condition="'$(TargetstvOS)' == 'true'">$(DefineConstants);NO_NTAUTHENTICATION</DefineConstants>
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
     <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
     <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == ''">SR.PlatformNotSupported_NetMail</GeneratePlatformNotSupportedAssemblyMessage>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'tvOS'">$(DefineConstants);NO_NTAUTHENTICATION</DefineConstants>
   </PropertyGroup>
   <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="System\Net\Base64Stream.cs" />
@@ -78,12 +78,12 @@
              Link="Common\System\HexConverter.cs" />
   </ItemGroup>
 
-  <ItemGroup Condition="'$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="System\Net\Mail\SmtpClient.Browser.cs" />
   </ItemGroup>
 
   <!-- Non Browser specific files - internal and security -->
-  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetsBrowser)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'Browser'">
     <Compile Include="System\Net\Mail\SmtpClient.cs" />
     <Compile Include="System\Net\Mail\ISmtpAuthenticationModule.cs" />
     <Compile Include="System\Net\Mail\SmtpAuthenticationManager.cs" />
@@ -119,7 +119,7 @@
   </ItemGroup>
 
   <!-- NT authentication specific files -->
-  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetsBrowser)' != 'true' and '$(TargetstvOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'Browser' and '$(TargetPlatformIdentifier)' != 'tvOS'">
     <Compile Include="$(CommonPath)System\Net\ContextFlagsPal.cs"
              Link="Common\System\Net\ContextFlagsPal.cs" />
     <Compile Include="$(CommonPath)System\Net\NegotiationInfoClass.cs"
@@ -137,13 +137,13 @@
   </ItemGroup>
 
   <!-- Unix specific files -->
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'tvOS'">
     <Compile Include="$(CommonPath)System\Net\ContextAwareResult.Unix.cs"
              Link="Common\System\Net\ContextAwareResult.Unix.cs" />
   </ItemGroup>
 
   <!-- Unix specific files (NT Authentication) -->
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' and '$(TargetstvOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs"
              Link="Common\Interop\Unix\Interop.Libraries.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\System.Net.Security.Native\Interop.GssBuffer.cs"
@@ -177,7 +177,7 @@
   </ItemGroup>
 
   <!-- Windows specific files -->
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)System\Net\Security\SecurityBuffer.Windows.cs"
              Link="Common\System\Net\Security\SecurityBuffer.Windows.cs" />
     <Compile Include="$(CommonPath)System\Net\Security\SecurityBufferType.Windows.cs"
diff --git a/src/libraries/System.Net.Mail/tests/Unit/System.Net.Mail.Unit.Tests.csproj b/src/libraries/System.Net.Mail/tests/Unit/System.Net.Mail.Unit.Tests.csproj
index 400d614c0dfa5..6ecf5f0bdd188 100644
--- a/src/libraries/System.Net.Mail/tests/Unit/System.Net.Mail.Unit.Tests.csproj
+++ b/src/libraries/System.Net.Mail/tests/Unit/System.Net.Mail.Unit.Tests.csproj
@@ -19,7 +19,7 @@
     <Compile Include="MessageTests\MessageHeaderBehaviorTest.cs" />
     <Compile Include="MessageTests\ReplyToListTest.cs" />
     <Compile Include="QuotedPrintableStreamTest.cs" />
-    <Compile Include="SmtpConnectionTests\EhloParseExtensionsTest.cs" Condition="'$(TargetsBrowser)' != 'true'" />
+    <Compile Include="SmtpConnectionTests\EhloParseExtensionsTest.cs" Condition="'$(TargetPlatformIdentifier)' != 'Browser'" />
     <Compile Include="SmtpDateTimeTest.cs" />
     <Compile Include="WriteStateInfoTest.cs" />
   </ItemGroup>
@@ -148,7 +148,7 @@
              Link="Common\System\HexConverter.cs" />
   </ItemGroup>
   <!-- Unix specific files -->
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Compile Include="$(CommonPath)System\Net\ContextAwareResult.Unix.cs"
              Link="Common\System\Net\ContextAwareResult.Unix.cs" />
     <Compile Include="$(CommonPath)System\Net\ContextFlagsAdapterPal.Unix.cs"
@@ -183,7 +183,7 @@
              Link="Common\System\Net\Security\Unix\SecChannelBindings.cs" />
   </ItemGroup>
   <!-- Windows specific files -->
-  <ItemGroup Condition="'$(TargetsWindows)'=='true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)Interop\Windows\Interop.BOOL.cs"
              Link="Common\Interop\Windows\Interop.BOOL.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\SChannel\Interop.SecPkgContext_ApplicationProtocol.cs"
@@ -265,7 +265,7 @@
   </ItemGroup>
 
   <!-- Non Browser specific files - internal and security -->
-  <ItemGroup Condition="'$(TargetsBrowser)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'Browser'">
     <Compile Include="..\..\src\System\Net\Mail\SmtpLoginAuthenticationModule.cs"
              Link="ProductionCode\SmtpLoginAuthenticationModule.cs" />
     <Compile Include="..\..\src\System\Net\Mail\SmtpNegotiateAuthenticationModule.cs"
diff --git a/src/libraries/System.Net.NameResolution/ref/System.Net.NameResolution.csproj b/src/libraries/System.Net.NameResolution/ref/System.Net.NameResolution.csproj
index 8c301a790a442..2dfb078c48a3d 100644
--- a/src/libraries/System.Net.NameResolution/ref/System.Net.NameResolution.csproj
+++ b/src/libraries/System.Net.NameResolution/ref/System.Net.NameResolution.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Net.NameResolution/src/System.Net.NameResolution.csproj b/src/libraries/System.Net.NameResolution/src/System.Net.NameResolution.csproj
index 250bc924fbd89..31a4fa7072e4b 100644
--- a/src/libraries/System.Net.NameResolution/src/System.Net.NameResolution.csproj
+++ b/src/libraries/System.Net.NameResolution/src/System.Net.NameResolution.csproj
@@ -8,7 +8,7 @@
   <PropertyGroup>
     <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
     <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == 'Browser' or '$(TargetPlatformIdentifier)' == ''">SR.SystemNetNameResolution_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
-    <ApiExclusionListPath Condition="'$(TargetsBrowser)' == 'true'">ExcludeApiList.PNSE.Browser.txt</ApiExclusionListPath>
+    <ApiExclusionListPath Condition="'$(TargetPlatformIdentifier)' == 'Browser'">ExcludeApiList.PNSE.Browser.txt</ApiExclusionListPath>
   </PropertyGroup>
   <ItemGroup Condition="'$(GeneratePlatformNotSupportedAssemblyMessage)' == ''">
     <Compile Include="System\Net\Dns.cs" />
@@ -36,7 +36,7 @@
     <Compile Include="$(CommonPath)System\Net\SocketProtocolSupportPal.cs"
              Link="Common\System\Net\SocketProtocolSupportPal.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\Net\NameResolutionPal.Windows.cs" />
     <!-- Debug only -->
     <Compile Include="$(CommonPath)System\Net\DebugSafeHandle.cs"
@@ -76,7 +76,7 @@
     <Compile Include="$(CommonPath)Interop\Windows\WinSock\Interop.GetAddrInfoExW.cs"
              Link="Common\Interop\Windows\WinSock\Interop.GetAddrInfoExW.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Compile Include="System\Net\NameResolutionPal.Unix.cs" />
     <Compile Include="$(CommonPath)System\Net\InteropIPAddressExtensions.Unix.cs"
              Link="Common\System\Net\InteropIPAddressExtensions.Unix.cs" />
@@ -109,7 +109,7 @@
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.SocketAddress.cs"
              Link="Common\Interop\Unix\System.Native\Interop.SocketAddress.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="System\Net\Dns.Browser.cs" />
   </ItemGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Net.NameResolution/tests/PalTests/System.Net.NameResolution.Pal.Tests.csproj b/src/libraries/System.Net.NameResolution/tests/PalTests/System.Net.NameResolution.Pal.Tests.csproj
index 7adb69687b6b8..13bdf57acf38f 100644
--- a/src/libraries/System.Net.NameResolution/tests/PalTests/System.Net.NameResolution.Pal.Tests.csproj
+++ b/src/libraries/System.Net.NameResolution/tests/PalTests/System.Net.NameResolution.Pal.Tests.csproj
@@ -21,9 +21,9 @@
     <Compile Include="Fakes\IPAddressFakeExtensions.cs" />
     <Compile Include="$(CommonPath)System\Net\Logging\NetEventSource.Common.cs"
              Link="Common\System\Net\Logging\NetEventSource.cs" />
-    <Compile Include="$(CommonPath)System\Net\Sockets\ProtocolType.cs" Condition="'$(TargetsWindows)' == 'true'"
+    <Compile Include="$(CommonPath)System\Net\Sockets\ProtocolType.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'"
              Link="Common\System\Net\Sockets\ProtocolType.cs" />
-    <Compile Include="$(CommonPath)System\Net\Sockets\SocketType.cs" Condition="'$(TargetsWindows)' == 'true'"
+    <Compile Include="$(CommonPath)System\Net\Sockets\SocketType.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'"
              Link="Common\System\Net\Sockets\SocketType.cs" />
     <Compile Include="$(CommonPath)System\Net\IPEndPointStatics.cs"
              Link="Common\System\Net\IPEndPointStatics.cs" />
@@ -36,7 +36,7 @@
     <Compile Include="$(CommonTestPath)System\Net\Configuration.Http.cs"
              Link="Common\System\Net\Configuration.Http.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsWindows)' == 'true' ">
+  <ItemGroup Condition=" '$(TargetPlatformIdentifier)' == 'windows' ">
     <Compile Include="..\..\src\System\Net\NameResolutionPal.Windows.cs"
              Link="ProductionCode\System\Net\NameResolutionPal.Windows.cs" />
     <Compile Include="$(CommonPath)System\Net\InternalException.cs"
@@ -74,7 +74,7 @@
     <Compile Include="$(CommonPath)Interop\Windows\WinSock\Interop.GetAddrInfoExW.cs"
              Link="Common\Interop\Windows\WinSock\Interop.GetAddrInfoExW.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="$(CommonPath)System\Net\SocketAddressPal.Unix.cs"
              Link="Common\System\Net\Internals\SocketAddressPal.Unix.cs" />
     <Compile Include="$(CommonPath)Interop\Interop.CheckedAccess.cs"
diff --git a/src/libraries/System.Net.NetworkInformation/ref/System.Net.NetworkInformation.csproj b/src/libraries/System.Net.NetworkInformation/ref/System.Net.NetworkInformation.csproj
index 2718a2752d42d..f19960917d7b2 100644
--- a/src/libraries/System.Net.NetworkInformation/ref/System.Net.NetworkInformation.csproj
+++ b/src/libraries/System.Net.NetworkInformation/ref/System.Net.NetworkInformation.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Net.NetworkInformation/src/System.Net.NetworkInformation.csproj b/src/libraries/System.Net.NetworkInformation/src/System.Net.NetworkInformation.csproj
index 66bcfce21b428..4a0125314b19e 100644
--- a/src/libraries/System.Net.NetworkInformation/src/System.Net.NetworkInformation.csproj
+++ b/src/libraries/System.Net.NetworkInformation/src/System.Net.NetworkInformation.csproj
@@ -4,10 +4,12 @@
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Linux;$(NetCoreAppCurrent)-Android;$(NetCoreAppCurrent)-OSX;$(NetCoreAppCurrent)-iOS;$(NetCoreAppCurrent)-tvOS;$(NetCoreAppCurrent)-FreeBSD;$(NetCoreAppCurrent)-illumos;$(NetCoreAppCurrent)-Solaris;$(NetCoreAppCurrent)</TargetFrameworks>
     <Nullable>enable</Nullable>
   </PropertyGroup>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsAnyOS)' == 'true'">SR.SystemNetNetworkInformation_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == ''">SR.SystemNetNetworkInformation_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="System\Net\NetworkInformation\DuplicateAddressDetectionState.cs" />
     <Compile Include="System\Net\NetworkInformation\GatewayIPAddressInformation.cs" />
     <Compile Include="System\Net\NetworkInformation\GatewayIPAddressInformationCollection.cs" />
@@ -26,7 +28,7 @@
     <Compile Include="System\Net\NetworkInformation\MulticastIPAddressInformationCollection.cs" />
     <Compile Include="System\Net\NetworkInformation\NetBiosNodeType.cs" />
     <Compile Include="System\Net\NetworkInformation\NetEventSource.NetworkInformation.cs" />
-    <Compile Include="System\Net\NetworkInformation\NetworkAddressChange.cs" Condition="'$(Targetsillumos)' != 'true' and '$(TargetsSolaris)' != 'true'" />
+    <Compile Include="System\Net\NetworkInformation\NetworkAddressChange.cs" Condition="'$(TargetPlatformIdentifier)' != 'illumos' and '$(TargetPlatformIdentifier)' != 'Solaris'" />
     <Compile Include="System\Net\NetworkInformation\NetworkAvailabilityEventArgs.cs" />
     <Compile Include="System\Net\NetworkInformation\NetworkChangeDelegates.cs" />
     <Compile Include="System\Net\NetworkInformation\NetworkInterface.cs" />
@@ -52,7 +54,7 @@
     <Compile Include="$(CommonPath)System\HexConverter.cs" Link="Common\System\HexConverter.cs" />
     <Compile Include="$(CommonPath)System\Threading\Tasks\TaskToApm.cs" Link="Common\System\Threading\Tasks\TaskToApm.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <!-- Logging -->
     <Compile Include="$(CommonPath)System\Net\Logging\NetEventSource.Common.cs" Link="Common\System\Net\Logging\NetEventSource.Common.cs" />
     <!-- Interop -->
@@ -97,7 +99,7 @@
     <Compile Include="$(CommonPath)Interop\Windows\WinSock\Interop.WSAIoctl.cs" Link="Common\Interop\Windows\WinSock\Interop.WSAIoctl.cs" />
   </ItemGroup>
   <!-- Unix -->
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows'">
     <Compile Include="System\Net\NetworkInformation\IPAddressUtil.cs" />
     <Compile Include="System\Net\NetworkInformation\NetworkFiles.cs" />
     <Compile Include="System\Net\NetworkInformation\SimpleGatewayIPAddressInformation.Unix.cs" />
@@ -121,7 +123,7 @@
     <Compile Include="$(CommonPath)System\IO\RowConfigReader.cs" Link="Common\System\IO\RowConfigReader.cs" />
   </ItemGroup>
   <!-- Linux (other than Android) -->
-  <ItemGroup Condition="'$(TargetsLinux)' == 'true' and '$(TargetsAndroid)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Linux'">
     <Compile Include="System\Net\NetworkInformation\ExceptionHelper.Linux.cs" />
     <Compile Include="System\Net\NetworkInformation\LinuxIcmpV4Statistics.cs" />
     <Compile Include="System\Net\NetworkInformation\LinuxIcmpV6Statistics.cs" />
@@ -147,7 +149,7 @@
     <Compile Include="$(CommonPath)Interop\Linux\Interop.LinuxNetDeviceFlags.cs" Link="Common\Interop\Linux\Interop.LinuxNetDeviceFlags.cs" />
   </ItemGroup>
   <!-- Android -->
-  <ItemGroup Condition="'$(TargetsAndroid)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Android'">
     <Compile Include="System\Net\NetworkInformation\IPGlobalPropertiesPal.Android.cs" />
     <Compile Include="System\Net\NetworkInformation\AndroidIPGlobalProperties.cs" />
     <Compile Include="System\Net\NetworkInformation\AndroidIPGlobalStatistics.cs" />
@@ -158,7 +160,7 @@
     <Compile Include="System\Net\NetworkInformation\AndroidNetworkInterface.cs" />
   </ItemGroup>
   <!-- OSX -->
-  <ItemGroup Condition="'$(TargetsOSX)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true' or '$(TargetsFreeBSD)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'OSX' or '$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'tvOS' or '$(TargetPlatformIdentifier)' == 'FreeBSD'">
     <Compile Include="System\Net\NetworkInformation\IPGlobalPropertiesPal.Bsd.cs" />
     <Compile Include="System\Net\NetworkInformation\NetworkInterfacePal.Bsd.cs" />
     <Compile Include="System\Net\NetworkInformation\BsdIcmpV4Statistics.cs" />
@@ -177,7 +179,7 @@
     <Compile Include="$(CommonPath)Interop\BSD\System.Native\Interop.ProtocolStatistics.cs" Link="Common\Interop\BSD\System.Native\Interop.ProtocolStatistics.cs" />
     <Compile Include="$(CommonPath)Interop\BSD\System.Native\Interop.TcpConnectionInfo.cs" Link="Common\Interop\BSD\System.Native\Interop.TcpConnectionInfo.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsOSX)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'OSX' or '$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'tvOS'">
     <Compile Include="System\Net\NetworkInformation\NetworkAddressChange.OSX.cs" />
     <!-- OSX Common -->
     <Compile Include="$(CommonPath)Interop\OSX\Interop.CoreFoundation.cs" Link="Common\Interop\OSX\Interop.CoreFoundation.cs" />
@@ -186,15 +188,15 @@
     <Compile Include="$(CommonPath)Interop\OSX\Interop.SystemConfiguration.cs" Link="Common\Interop\OSX\Interop.SystemConfiguration.cs" />
     <Compile Include="$(CommonPath)Microsoft\Win32\SafeHandles\SafeCreateHandle.OSX.cs" Link="Common\Microsoft\Win32\SafeHandles\SafeCreateHandle.OSX.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsFreeBSD)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'FreeBSD'">
     <Compile Include="$(CommonPath)Interop\FreeBSD\Interop.Libraries.cs" Link="Common\Interop\FreeBSD\Interop.Libraries.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsLinux)' == 'true' or '$(TargetsFreeBSD)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Linux' or '$(TargetPlatformIdentifier)' == 'Android' or '$(TargetPlatformIdentifier)' == 'FreeBSD'">
     <Compile Include="System\Net\NetworkInformation\NetworkAddressChange.Unix.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.NetworkChange.cs" Link="Common\Interop\Unix\System.Native\Interop.NetworkChange.cs" />
   </ItemGroup>
   <!-- Unknown Unix -->
-  <ItemGroup Condition="'$(TargetsUnknownUnix)' == 'true' or '$(Targetsillumos)' == 'true' or '$(TargetsSolaris)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'UnknownUnix' or '$(TargetPlatformIdentifier)' == 'illumos' or '$(TargetPlatformIdentifier)' == 'Solaris'">
     <Compile Include="System\Net\NetworkInformation\IPGlobalPropertiesPal.UnknownUnix.cs" />
     <Compile Include="System\Net\NetworkInformation\NetworkInterfacePal.UnknownUnix.cs" />
     <Compile Include="System\Net\NetworkInformation\NetworkAddressChange.UnknownUnix.cs" />
@@ -217,11 +219,11 @@
     <Reference Include="System.Threading.Overlapped" />
     <Reference Include="System.Threading.ThreadPool" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows'">
     <Reference Include="System.IO.FileSystem" />
     <Reference Include="System.Threading.Thread" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsLinux)' == 'true' or '$(TargetsFreeBSD)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Linux' or '$(TargetPlatformIdentifier)' == 'Android' or '$(TargetPlatformIdentifier)' == 'FreeBSD'">
     <Reference Include="System.Threading.Timer" />
   </ItemGroup>
 </Project>
diff --git a/src/libraries/System.Net.Ping/ref/System.Net.Ping.csproj b/src/libraries/System.Net.Ping/ref/System.Net.Ping.csproj
index b91f82444f42e..3a766d263145e 100644
--- a/src/libraries/System.Net.Ping/ref/System.Net.Ping.csproj
+++ b/src/libraries/System.Net.Ping/ref/System.Net.Ping.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Net.Ping/src/System.Net.Ping.csproj b/src/libraries/System.Net.Ping/src/System.Net.Ping.csproj
index 206fe170799c1..076d8bcd974b5 100644
--- a/src/libraries/System.Net.Ping/src/System.Net.Ping.csproj
+++ b/src/libraries/System.Net.Ping/src/System.Net.Ping.csproj
@@ -4,11 +4,13 @@
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent)-OSX;$(NetCoreAppCurrent)-iOS;$(NetCoreAppCurrent)-tvOS;$(NetCoreAppCurrent)</TargetFrameworks>
     <Nullable>enable</Nullable>
   </PropertyGroup>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsAnyOS)' == 'true'">SR.SystemNetPing_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
-    <TargetsApple Condition="'$(TargetsOSX)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true'">true</TargetsApple>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == ''">SR.SystemNetPing_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <IsApplePlatform Condition="'$(TargetPlatformIdentifier)' == 'OSX' or '$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'tvOS'">true</IsApplePlatform>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="System\Net\NetworkInformation\IPStatus.cs" />
     <Compile Include="System\Net\NetworkInformation\NetEventSource.Ping.cs" />
     <Compile Include="System\Net\NetworkInformation\Ping.cs" />
@@ -37,7 +39,7 @@
     <Compile Include="$(CommonPath)System\Net\Internals\IPEndPointExtensions.cs"
              Link="Common\System\Net\Internals\IPEndPointExtensions.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="('$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows')">
     <Compile Include="System\Net\NetworkInformation\IcmpV4MessageConstants.cs" />
     <Compile Include="System\Net\NetworkInformation\IcmpV6MessageConstants.cs" />
     <Compile Include="System\Net\NetworkInformation\Ping.RawSocket.cs" />
@@ -68,14 +70,14 @@
     <Compile Include="$(CommonPath)System\Text\ValueUtf8Converter.cs"
              Link="Common\System\Text\ValueUtf8Converter.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' AND '$(TargetsApple)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows' and '$(IsApplePlatform)' != 'true'">
     <Compile Include="System\Net\NetworkInformation\Ping.Unix.cs" />
     <Compile Include="System\Net\NetworkInformation\Ping.PingUtility.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' AND '$(TargetsApple)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows' and '$(IsApplePlatform)' == 'true'">
     <Compile Include="System\Net\NetworkInformation\Ping.OSX.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\Net\NetworkInformation\Ping.Windows.cs" />
     <!-- System.Net Common -->
     <Compile Include="$(CommonPath)System\Net\SocketAddressPal.Windows.cs"
@@ -119,7 +121,7 @@
     <Reference Include="System.Threading" />
     <Reference Include="System.Threading.ThreadPool" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows'">
     <Reference Include="System.Collections.Specialized" />
     <Reference Include="System.Diagnostics.Process" />
     <Reference Include="System.IO.FileSystem" />
diff --git a/src/libraries/System.Net.Primitives/ref/System.Net.Primitives.csproj b/src/libraries/System.Net.Primitives/ref/System.Net.Primitives.csproj
index da2cdd8e41a4e..a52552a435c7a 100644
--- a/src/libraries/System.Net.Primitives/ref/System.Net.Primitives.csproj
+++ b/src/libraries/System.Net.Primitives/ref/System.Net.Primitives.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Net.Primitives/src/System.Net.Primitives.csproj b/src/libraries/System.Net.Primitives/src/System.Net.Primitives.csproj
index cbb369186fa27..3c17ba5634a47 100644
--- a/src/libraries/System.Net.Primitives/src/System.Net.Primitives.csproj
+++ b/src/libraries/System.Net.Primitives/src/System.Net.Primitives.csproj
@@ -87,7 +87,7 @@
     <Compile Include="$(CommonPath)Interop\Windows\WinSock\Interop.ErrorCodes.cs"
              Link="Common\Interop\Windows\WinSock\Interop.ErrorCodes.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\Net\SocketException.Windows.cs" />
     <Compile Include="$(CommonPath)System\Net\SocketAddressPal.Windows.cs"
              Link="Common\System\Net\SocketAddressPal.Windows.cs" />
@@ -110,7 +110,7 @@
     <Compile Include="$(CommonPath)Interop\Windows\IpHlpApi\Interop.if_nametoindex.cs"
              Link="Common\Interop\Windows\IpHlpApi\Interop.if_nametoindex.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="System\Net\SocketException.Unix.cs" />
     <Compile Include="$(CommonPath)System\Net\SocketAddressPal.Unix.cs"
              Link="Common\System\Net\SocketAddressPal.Unix.cs" />
@@ -125,7 +125,7 @@
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.SocketAddress.cs"
              Link="Common\Interop\Unix\System.Native\Interop.SocketAddress.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Compile Include="$(CommonPath)System\Net\NetworkInformation\HostInformationPal.Unix.cs"
              Link="Common\System\Net\NetworkInformation\HostInformationPal.Unix.cs" />
     <Compile Include="$(CommonPath)System\Net\NetworkInformation\InterfaceInfoPal.Unix.cs"
@@ -141,7 +141,7 @@
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.InterfaceNameToIndex.cs"
              Link="Common\Interop\Unix\System.Native\Interop.InterfaceNameToIndex.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="$(CommonPath)System\Net\NetworkInformation\HostInformationPal.Browser.cs"
              Link="Common\System\Net\NetworkInformation\HostInformationPal.Browser.cs" />
     <Compile Include="$(CommonPath)System\Net\NetworkInformation\InterfaceInfoPal.Browser.cs"
diff --git a/src/libraries/System.Net.Primitives/tests/PalTests/System.Net.Primitives.Pal.Tests.csproj b/src/libraries/System.Net.Primitives/tests/PalTests/System.Net.Primitives.Pal.Tests.csproj
index fc4e4d4e55f4e..2f413fd0a913c 100644
--- a/src/libraries/System.Net.Primitives/tests/PalTests/System.Net.Primitives.Pal.Tests.csproj
+++ b/src/libraries/System.Net.Primitives/tests/PalTests/System.Net.Primitives.Pal.Tests.csproj
@@ -55,7 +55,7 @@
     <Compile Include="$(CommonPath)Interop\Windows\WinSock\Interop.ErrorCodes.cs"
              Link="ProductionCode\Common\Interop\Windows\WinSock\Interop.ErrorCodes.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsWindows)' == 'true' ">
+  <ItemGroup Condition=" '$(TargetPlatformIdentifier)' == 'windows' ">
     <Compile Include="..\..\src\System\Net\SocketException.Windows.cs"
              Link="ProductionCode\System\Net\SocketException.Windows.cs" />
     <Compile Include="$(CommonPath)System\Net\SocketAddressPal.Windows.cs"
@@ -79,7 +79,7 @@
     <Compile Include="$(CommonPath)Interop\Windows\IpHlpApi\Interop.if_nametoindex.cs"
              Link="ProductionCode\Common\Interop\Windows\IpHlpApi\Interop.if_nametoindex.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="..\..\src\System\Net\SocketException.Unix.cs"
              Link="ProductionCode\System\Net\SocketException.Unix.cs" />
     <Compile Include="$(CommonPath)System\Net\SocketAddressPal.Unix.cs"
@@ -97,7 +97,7 @@
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.SocketAddress.cs"
              Link="ProductionCode\Common\Interop\Unix\System.Native\Interop.SocketAddress.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Compile Include="$(CommonPath)System\Net\NetworkInformation\HostInformationPal.Unix.cs"
              Link="Common\System\Net\NetworkInformation\HostInformationPal.Unix.cs" />
     <Compile Include="$(CommonPath)System\Net\NetworkInformation\InterfaceInfoPal.Unix.cs"
@@ -113,7 +113,7 @@
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.InterfaceNameToIndex.cs"
              Link="Common\Interop\Unix\System.Native\Interop.InterfaceNameToIndex.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="$(CommonPath)System\Net\NetworkInformation\HostInformationPal.Browser.cs"
              Link="Common\System\Net\NetworkInformation\HostInformationPal.Browser.cs" />
     <Compile Include="$(CommonPath)System\Net\NetworkInformation\InterfaceInfoPal.Browser.cs"
diff --git a/src/libraries/System.Net.Primitives/tests/UnitTests/System.Net.Primitives.UnitTests.Tests.csproj b/src/libraries/System.Net.Primitives/tests/UnitTests/System.Net.Primitives.UnitTests.Tests.csproj
index 4e77239fae905..a070c4488abe8 100644
--- a/src/libraries/System.Net.Primitives/tests/UnitTests/System.Net.Primitives.UnitTests.Tests.csproj
+++ b/src/libraries/System.Net.Primitives/tests/UnitTests/System.Net.Primitives.UnitTests.Tests.csproj
@@ -77,7 +77,7 @@
     <Compile Include="$(CommonPath)Interop\Windows\WinSock\Interop.ErrorCodes.cs"
              Link="ProductionCode\Common\Interop\Windows\WinSock\Interop.ErrorCodes.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition=" '$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="..\..\src\System\Net\SocketException.Windows.cs"
              Link="ProductionCode\System\Net\SocketException.Unix.cs" />
     <Compile Include="$(CommonPath)System\Net\SocketAddressPal.Windows.cs"
@@ -89,7 +89,7 @@
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
              Link="ProductionCode\Common\Interop\Windows\Interop.Libraries.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="..\..\src\System\Net\SocketException.Unix.cs"
              Link="ProductionCode\System\Net\SocketException.Unix.cs" />
     <Compile Include="$(CommonPath)System\Net\NetworkInformation\InterfaceInfoPal.Unix.cs"
diff --git a/src/libraries/System.Net.Quic/ref/System.Net.Quic.csproj b/src/libraries/System.Net.Quic/ref/System.Net.Quic.csproj
index 507e003a13efa..1d0cdaed9f8f0 100644
--- a/src/libraries/System.Net.Quic/ref/System.Net.Quic.csproj
+++ b/src/libraries/System.Net.Quic/ref/System.Net.Quic.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
     <IsNETCoreAppRef>false</IsNETCoreAppRef>
   </PropertyGroup>
diff --git a/src/libraries/System.Net.Quic/src/System.Net.Quic.csproj b/src/libraries/System.Net.Quic/src/System.Net.Quic.csproj
index 31e565288099d..12bcced0a5f97 100644
--- a/src/libraries/System.Net.Quic/src/System.Net.Quic.csproj
+++ b/src/libraries/System.Net.Quic/src/System.Net.Quic.csproj
@@ -3,14 +3,15 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Linux;$(NetCoreAppCurrent)-OSX;$(NetCoreAppCurrent)-FreeBSD;$(NetCoreAppCurrent)</TargetFrameworks>
     <Nullable>enable</Nullable>
-    <DefineConstants Condition="'$(TargetsFreeBSD)' == 'true' or '$(TargetsOSX)' == 'true'">$(DefineConstants);SOCKADDR_HAS_LENGTH</DefineConstants>
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsAnyOS)' == 'true'">SR.SystemNetQuic_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'FreeBSD' or '$(TargetPlatformIdentifier)' == 'OSX'">$(DefineConstants);SOCKADDR_HAS_LENGTH</DefineConstants>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == ''">SR.SystemNetQuic_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
   <!-- Source files -->
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="System\Net\Quic\*.cs" />
     <Compile Include="System\Net\Quic\Implementations\*.cs" />
     <Compile Include="System\Net\Quic\Implementations\Mock\*.cs" />
@@ -30,9 +31,7 @@
     <Compile Include="$(CommonPath)DisableRuntimeMarshalling.cs">
       <Link>Common\DisableRuntimeMarshalling.cs</Link>
     </Compile>
-  </ItemGroup>
-  <!-- System.Net common -->
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true'">
+    <!-- System.Net common -->
     <Compile Include="$(CommonPath)System\Threading\Tasks\TaskToApm.cs" Link="Common\System\Threading\Tasks\TaskToApm.cs" />
     <Compile Include="$(CommonPath)System\Net\ArrayBuffer.cs" Link="Common\System\Net\ArrayBuffer.cs" />
     <Compile Include="$(CommonPath)System\Net\MultiArrayBuffer.cs" Link="Common\System\Net\MultiArrayBuffer.cs" />
@@ -40,7 +39,7 @@
     <Compile Include="$(CommonPath)System\Net\StreamBuffer.cs" Link="Common\System\Net\StreamBuffer.cs" />
   </ItemGroup>
   <!-- Windows specific files -->
-  <ItemGroup Condition=" '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs" Link="Common\Interop\Windows\Interop.Libraries.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Crypt32\Interop.CERT_CONTEXT.cs" Link="Common\Interop\Windows\Crypt32\Interop.CERT_CONTEXT.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Crypt32\Interop.CERT_INFO.cs" Link="Common\Interop\Windows\Crypt32\Interop.CERT_INFO.cs" />
@@ -56,7 +55,7 @@
     <Compile Include="System\Net\Quic\Implementations\MsQuic\Interop\MsQuicStatusCodes.Windows.cs" />
   </ItemGroup>
   <!-- Unix (OSX + Linux) specific files -->
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Linux' or '$(TargetPlatformIdentifier)' == 'OSX' or '$(TargetPlatformIdentifier)' == 'FreeBSD'">
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs" Link="Common\Interop\Unix\Interop.Libraries.cs" />
      <Compile Include="$(CommonPath)Interop\Unix\System.Security.Cryptography.Native\Interop.ASN1.cs" Link="Common\Interop\Unix\System.Security.Cryptography.Native\Interop.ASN1.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\System.Security.Cryptography.Native\Interop.BIO.cs" Link="Common\Interop\Unix\System.Security.Cryptography.Native\Interop.BIO.cs" />
@@ -82,20 +81,20 @@
     <Compile Include="$(CommonPath)Microsoft\Win32\SafeHandles\SafeHandleCache.cs" Link="Common\Microsoft\Win32\SafeHandles\SafeHandleCache.cs" />
   </ItemGroup>
   <!-- Linux specific files -->
-  <ItemGroup Condition="'$(TargetsLinux)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Linux'">
     <Compile Include="$(CommonPath)Interop\Linux\Interop.Libraries.cs" Link="Common\Interop\Linux\Interop.Libraries.cs" />
     <Compile Include="System\Net\Quic\Implementations\MsQuic\Interop\MsQuicStatusCodes.Linux.cs" />
     <Compile Include="$(CommonPath)System\Net\Security\CertificateValidation.Unix.cs" Link="Common\System\Net\Security\CertificateValidation.Unix.cs" />
   </ItemGroup>
   <!-- FreeBSD specific files -->
-  <ItemGroup Condition="'$(TargetsFreeBSD)' == 'true' ">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'FreeBSD' ">
     <Compile Include="$(CommonPath)System\Net\Security\CertificateValidation.Unix.cs" Link="Common\System\Net\Security\CertificateValidation.Unix.cs" />
     <Compile Include="$(CommonPath)Interop\FreeBSD\Interop.Libraries.cs" Link="Common\Interop\FreeBSD\Interop.Libraries.cs" />
     <!-- Assume similarity with OSX for now -->
     <Compile Include="System\Net\Quic\Implementations\MsQuic\Interop\MsQuicStatusCodes.OSX.cs" />
   </ItemGroup>
   <!-- OSX specific files -->
-  <ItemGroup Condition=" '$(TargetsOSX)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'OSX'">
     <Compile Include="$(CommonPath)System\Net\Security\CertificateValidation.OSX.cs" Link="Common\System\Net\Security\CertificateValidation.OSX.cs" />
     <Compile Include="$(CommonPath)Interop\OSX\Interop.Libraries.cs" Link="Common\Interop\OSX\Interop.Libraries.cs" />
     <Compile Include="System\Net\Quic\Implementations\MsQuic\Interop\MsQuicStatusCodes.OSX.cs" />
@@ -130,13 +129,13 @@
     <Reference Include="System.Threading.Channels" />
   </ItemGroup>
 
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Linux' or '$(TargetPlatformIdentifier)' == 'OSX' or '$(TargetPlatformIdentifier)' == 'FreeBSD'">
     <Reference Include="System.Diagnostics.StackTrace" Condition="'$(Configuration)' == 'Debug'" />
     <Reference Include="System.Security.Cryptography.OpenSsl" />
   </ItemGroup>
 
   <!-- Support for deploying msquic -->
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true' and
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows' and
                         ('$(TargetArchitecture)' == 'x64' or '$(TargetArchitecture)' == 'x86') and '$(DotNetBuildFromSource)' != 'true'">
     <BinPlaceDir Include="$(MicrosoftNetCoreAppRuntimePackNativeDir)" ItemName="NativeBinPlaceItem" />
     <BinPlaceDir Include="$(NetCoreAppCurrentTestHostSharedFrameworkPath)" ItemName="NativeBinPlaceItem" />
diff --git a/src/libraries/System.Net.Requests/ref/System.Net.Requests.csproj b/src/libraries/System.Net.Requests/ref/System.Net.Requests.csproj
index 78b1a6fa04b1d..36d4f9a3d0353 100644
--- a/src/libraries/System.Net.Requests/ref/System.Net.Requests.csproj
+++ b/src/libraries/System.Net.Requests/ref/System.Net.Requests.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <!-- SYSLIB0014: WebRequest, HttpWebRequest, ServicePoint, and WebClient are obsolete. Use HttpClient instead. -->
     <NoWarn>$(NoWarn);CS0809;SYSLIB0014</NoWarn>
     <Nullable>enable</Nullable>
diff --git a/src/libraries/System.Net.Requests/src/System.Net.Requests.csproj b/src/libraries/System.Net.Requests/src/System.Net.Requests.csproj
index fabcc644d972a..d2c9530d5f6bd 100644
--- a/src/libraries/System.Net.Requests/src/System.Net.Requests.csproj
+++ b/src/libraries/System.Net.Requests/src/System.Net.Requests.csproj
@@ -78,20 +78,19 @@
     <Compile Include="$(CommonPath)System\Threading\Tasks\TaskToApm.cs"
              Link="Common\System\Threading\Tasks\TaskToApm.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)Interop\Windows\WinInet\Interop.wininet_errors.cs"
              Link="Common\Interop\Windows\WinInet\Interop.wininet_errors.cs" />
     <Compile Include="$(CommonPath)System\Net\ContextAwareResult.Windows.cs"
              Link="Common\System\Net\ContextAwareResult.Windows.cs" />
     <Compile Include="System\Net\WebExceptionPal.Windows.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Compile Include="$(CommonPath)System\Net\ContextAwareResult.Unix.cs"
              Link="Common\System\Net\ContextAwareResult.Unix.cs" />
     <Compile Include="System\Net\WebExceptionPal.Unix.cs" />
   </ItemGroup>
   <ItemGroup>
-    <ProjectReference Include="$(LibrariesProjectRoot)System.Security.Principal.Windows\src\System.Security.Principal.Windows.csproj" />
     <Reference Include="Microsoft.Win32.Primitives" />
     <Reference Include="System.Collections" />
     <Reference Include="System.Collections.NonGeneric" />
@@ -110,6 +109,7 @@
     <Reference Include="System.Security.Claims" />
     <Reference Include="System.Security.Cryptography" />
     <Reference Include="System.Security.Principal" />
+    <Reference Include="System.Security.Principal.Windows" />
     <Reference Include="System.Threading" />
     <Reference Include="System.Threading.Thread" />
   </ItemGroup>
diff --git a/src/libraries/System.Net.Security/ref/System.Net.Security.csproj b/src/libraries/System.Net.Security/ref/System.Net.Security.csproj
index f5519a69b6028..9c747a8b91e28 100644
--- a/src/libraries/System.Net.Security/ref/System.Net.Security.csproj
+++ b/src/libraries/System.Net.Security/ref/System.Net.Security.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Net.Security/src/System.Net.Security.csproj b/src/libraries/System.Net.Security/src/System.Net.Security.csproj
index a71d01bc0b794..b33246299b9da 100644
--- a/src/libraries/System.Net.Security/src/System.Net.Security.csproj
+++ b/src/libraries/System.Net.Security/src/System.Net.Security.csproj
@@ -4,20 +4,18 @@
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent)-Android;$(NetCoreAppCurrent)-OSX;$(NetCoreAppCurrent)-iOS;$(NetCoreAppCurrent)-tvOS;$(NetCoreAppCurrent)</TargetFrameworks>
     <!-- This is needed so that code for TlsCipherSuite will have no namespace (causes compile errors) when used within T4 template  -->
     <DefineConstants>$(DefineConstants);PRODUCT</DefineConstants>
-    <DefineConstants Condition="'$(TargetsWindows)' == 'true'">$(DefineConstants);TARGET_WINDOWS</DefineConstants>
     <Nullable>enable</Nullable>
   </PropertyGroup>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsAnyOS)' == 'true'">SR.SystemNetSecurity_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == ''">SR.SystemNetSecurity_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'windows'">$(DefineConstants);TARGET_WINDOWS</DefineConstants>
+    <UseAndroidCrypto Condition="'$(TargetPlatformIdentifier)' == 'Android'">true</UseAndroidCrypto>
+    <UseAppleCrypto Condition="'$(TargetPlatformIdentifier)' == 'OSX' or '$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'tvOS'">true</UseAppleCrypto>
+    <DefineConstants Condition="'$(UseAndroidCrypto)' == 'true' or '$(UseAppleCrypto)' == 'true'">$(DefineConstants);SYSNETSECURITY_NO_OPENSSL</DefineConstants>
   </PropertyGroup>
-  <PropertyGroup>
-    <UseAndroidCrypto Condition="'$(TargetsAndroid)' == 'true'">true</UseAndroidCrypto>
-    <UseAppleCrypto Condition="'$(TargetsOSX)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true'">true</UseAppleCrypto>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(UseAndroidCrypto)' == 'true' or '$(UseAppleCrypto)' == 'true'">
-    <DefineConstants>$(DefineConstants);SYSNETSECURITY_NO_OPENSSL</DefineConstants>
-  </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="System\Net\CertificateValidationPal.cs" />
     <Compile Include="System\Net\Logging\NetEventSource.cs" />
     <Compile Include="System\Net\SslStreamContext.cs" />
@@ -100,7 +98,7 @@
   <!-- This file depends on IANA registry. We do not want anyone's build to break after the update -->
   <!-- or if they don't have internet connection - explicit opt-in required -->
   <!-- To expose newly generated APIs, generated file have to be deliberately copied -->
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="System\Net\Security\TlsCipherSuite.cs">
       <DesignTime>True</DesignTime>
       <AutoGen>True</AutoGen>
@@ -108,14 +106,14 @@
     </Compile>
     <None Include="System\Net\Security\TlsCipherSuiteNameParser.ttinclude" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows'">
     <Compile Include="System\Net\Security\TlsCipherSuiteData.Lookup.cs">
       <DesignTime>True</DesignTime>
       <AutoGen>True</AutoGen>
       <DependentUpon>TlsCipherSuiteData.Lookup.tt</DependentUpon>
     </Compile>
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <None Include="System\Net\Security\TlsCipherSuiteData.Lookup.cs">
       <DesignTime>True</DesignTime>
       <AutoGen>True</AutoGen>
@@ -136,7 +134,7 @@
     <None Include="System\Net\Security\TlsCipherSuite.tt" />
     <None Include="System\Net\Security\TlsCipherSuiteData.Lookup.tt" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\Net\CertificateValidationPal.Windows.cs" />
     <Compile Include="System\Net\Security\CipherSuitesPolicyPal.Windows.cs" />
     <Compile Include="System\Net\Security\NegotiateStreamPal.Windows.cs" />
@@ -240,7 +238,7 @@
     <Compile Include="$(CommonPath)Interop\Windows\SspiCli\SecPkgContext_StreamSizes.cs"
              Link="Common\Interop\Windows\SspiCli\SecPkgContext_StreamSizes.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows'">
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs"
              Link="Common\Interop\Unix\Interop.Libraries.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Errors.cs"
@@ -262,7 +260,7 @@
     <Compile Include="System\Net\Security\SslConnectionInfo.Unix.cs" />
     <Compile Include="System\Net\Security\TlsCipherSuiteData.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' and '$(TargetstvOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows' and '$(TargetPlatformIdentifier)' != 'tvOS'">
     <Compile Include="$(CommonPath)Microsoft\Win32\SafeHandles\GssSafeHandles.cs"
              Link="Common\Microsoft\Win32\SafeHandles\GssSafeHandles.cs" />
     <Compile Include="$(CommonPath)System\Net\Security\Unix\SafeDeleteNegoContext.cs"
@@ -285,7 +283,7 @@
              Link="Common\System\Net\Security\NegotiateStreamPal.Unix.cs" />
     <Compile Include="System\Net\Security\NegotiateStreamPal.Unix.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetstvOS)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'tvOS'">
     <Compile Include="$(CommonPath)Microsoft\Win32\SafeHandles\GssSafeHandles.PlatformNotSupported.cs"
              Link="Common\Microsoft\Win32\SafeHandles\GssSafeHandles.PlatformNotSupported.cs" />
     <Compile Include="$(CommonPath)System\Net\ContextFlagsAdapterPal.PlatformNotSupported.cs"
@@ -294,7 +292,7 @@
              Link="Common\System\Net\Security\NegotiateStreamPal.PlatformNotSupported.cs" />
     <Compile Include="System\Net\Security\NegotiateStreamPal.PlatformNotSupported.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' and '$(UseAndroidCrypto)' != 'true' and '$(UseAppleCrypto)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows' and '$(UseAndroidCrypto)' != 'true' and '$(UseAppleCrypto)' != 'true'">
     <Compile Include="System\Net\CertificateValidationPal.Unix.cs" />
     <Compile Include="System\Net\Security\CipherSuitesPolicyPal.Linux.cs" />
     <Compile Include="System\Net\Security\SslStreamPal.Unix.cs" />
@@ -433,7 +431,7 @@
     <Reference Include="System.Threading" />
     <Reference Include="System.Threading.ThreadPool" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows'">
     <Reference Include="System.Diagnostics.StackTrace" />
     <Reference Include="System.Security.Cryptography.Algorithms" />
     <Reference Include="System.Security.Cryptography" />
diff --git a/src/libraries/System.Net.Security/tests/FunctionalTests/System.Net.Security.Tests.csproj b/src/libraries/System.Net.Security/tests/FunctionalTests/System.Net.Security.Tests.csproj
index 72ef0e0c58132..8f2d6f40e17ef 100644
--- a/src/libraries/System.Net.Security/tests/FunctionalTests/System.Net.Security.Tests.csproj
+++ b/src/libraries/System.Net.Security/tests/FunctionalTests/System.Net.Security.Tests.csproj
@@ -10,7 +10,7 @@
   <ItemGroup>
     <Compile Include="AssemblyInfo.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsBrowser)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'Browser'">
     <Compile Include="DummyTcpServer.cs" />
     <Compile Include="SslStreamExtensions.cs" />
     <Compile Include="TestConfiguration.cs" />
@@ -107,18 +107,18 @@
     <Compile Include="SslStreamCredentialCacheTest.cs" />
     <Compile Include="SslStreamSystemDefaultsTest.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsBrowser)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'Browser'">
     <Compile Include="TelemetryTest.cs" />
     <Compile Include="LoggingTest.cs" />
     <Compile Include="$(CommonTestPath)System\Diagnostics\Tracing\TestEventListener.cs"
              Link="Common\System\Diagnostics\Tracing\TestEventListener.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="IdentityValidator.Windows.cs" />
     <Compile Include="$(CommonTestPath)System\Net\Capability.Security.Windows.cs"
              Link="Common\System\Net\Capability.Security.Windows.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'windows' and '$(TargetPlatformIdentifier)' != 'Browser'">
     <Compile Include="IdentityValidator.Unix.cs" />
     <Compile Include="$(CommonTestPath)System\Net\Capability.Security.Unix.cs"
              Link="Common\System\Net\Capability.Security.Unix.cs" />
diff --git a/src/libraries/System.Net.Security/tests/UnitTests/System.Net.Security.Unit.Tests.csproj b/src/libraries/System.Net.Security/tests/UnitTests/System.Net.Security.Unit.Tests.csproj
index 46056c9b64f28..0fd7b6b55f481 100644
--- a/src/libraries/System.Net.Security/tests/UnitTests/System.Net.Security.Unit.Tests.csproj
+++ b/src/libraries/System.Net.Security/tests/UnitTests/System.Net.Security.Unit.Tests.csproj
@@ -17,11 +17,11 @@
   <ItemGroup>
     <Compile Include="AssemblyInfo.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsAndroid)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Android'">
     <Compile Include="MD4Tests.cs" />
     <Compile Include="..\..\src\System\Net\Security\MD4.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsBrowser)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'Browser'">
     <Compile Include="SslApplicationProtocolTests.cs" />
     <Compile Include="SslAuthenticationOptionsTests.cs" />
     <Compile Include="SslStreamAllowedProtocolsTest.cs" />
@@ -38,7 +38,7 @@
     <Compile Include="$(CommonPath)System\HexConverter.cs"
              Link="Common\System\HexConverter.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsBrowser)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'Browser'">
     <!-- Production code references -->
     <Compile Include="..\..\src\System\Net\Security\NetEventSource.Security.cs"
              Link="ProductionCode\System\Net\Security\NetEventSource.Security.cs" />
diff --git a/src/libraries/System.Net.ServicePoint/ref/System.Net.ServicePoint.csproj b/src/libraries/System.Net.ServicePoint/ref/System.Net.ServicePoint.csproj
index 8041ebea6f80e..a7b78ca9ecacf 100644
--- a/src/libraries/System.Net.ServicePoint/ref/System.Net.ServicePoint.csproj
+++ b/src/libraries/System.Net.ServicePoint/ref/System.Net.ServicePoint.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Net.ServicePoint/src/System.Net.ServicePoint.csproj b/src/libraries/System.Net.ServicePoint/src/System.Net.ServicePoint.csproj
index b67c9ae2f0d41..659e23ec47d3e 100644
--- a/src/libraries/System.Net.ServicePoint/src/System.Net.ServicePoint.csproj
+++ b/src/libraries/System.Net.ServicePoint/src/System.Net.ServicePoint.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup Condition="'$(IsPartialFacadeAssembly)' != 'true'">
diff --git a/src/libraries/System.Net.Sockets/ref/System.Net.Sockets.csproj b/src/libraries/System.Net.Sockets/ref/System.Net.Sockets.csproj
index 9387aa994199f..0ca0235e6ca78 100644
--- a/src/libraries/System.Net.Sockets/ref/System.Net.Sockets.csproj
+++ b/src/libraries/System.Net.Sockets/ref/System.Net.Sockets.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Net.Sockets/src/System.Net.Sockets.csproj b/src/libraries/System.Net.Sockets/src/System.Net.Sockets.csproj
index a437542c5ffe1..4f2f27f215d0a 100644
--- a/src/libraries/System.Net.Sockets/src/System.Net.Sockets.csproj
+++ b/src/libraries/System.Net.Sockets/src/System.Net.Sockets.csproj
@@ -4,15 +4,17 @@
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent)</TargetFrameworks>
     <Nullable>enable</Nullable>
   </PropertyGroup>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsAnyOS)' == 'true'">SR.SystemNetSockets_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == ''">SR.SystemNetSockets_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
   <PropertyGroup>
     <!-- SYSTEM_NET_SOCKETS_DLL is required to allow source-level code sharing for types defined within the
          System.Net.Internals namespace. -->
     <DefineConstants>$(DefineConstants);SYSTEM_NET_SOCKETS_DLL</DefineConstants>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <!-- All configurations -->
     <Compile Include="System\Net\Sockets\SocketReceiveFromResult.cs" />
     <Compile Include="System\Net\Sockets\SocketReceiveMessageFromResult.cs" />
@@ -86,7 +88,7 @@
     <Compile Include="$(CommonPath)System\Net\Sockets\SocketType.cs"
              Link="Common\System\Net\Sockets\SocketType.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <!-- Windows: CoreCLR -->
     <Compile Include="System\Net\Sockets\DynamicWinsockMethods.cs" />
     <Compile Include="System\Net\Sockets\SafeSocketHandle.Windows.cs" />
@@ -177,7 +179,7 @@
     <Compile Include="$(CommonPath)System\Net\CompletionPortHelper.Windows.cs"
              Link="Common\System\Net\CompletionPortHelper.Windows.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Compile Include="System\Net\Sockets\SafeSocketHandle.Unix.cs" />
     <Compile Include="System\Net\Sockets\Socket.Unix.cs" />
     <Compile Include="System\Net\Sockets\SocketAsyncContext.Unix.cs" />
@@ -297,7 +299,7 @@
     <Reference Include="System.Threading.Overlapped" />
     <Reference Include="System.Threading.ThreadPool" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Reference Include="System.Threading.Thread" />
   </ItemGroup>
 </Project>
diff --git a/src/libraries/System.Net.Sockets/tests/FunctionalTests/System.Net.Sockets.Tests.csproj b/src/libraries/System.Net.Sockets/tests/FunctionalTests/System.Net.Sockets.Tests.csproj
index 63e0987f7ac1a..1d3155798c4f0 100644
--- a/src/libraries/System.Net.Sockets/tests/FunctionalTests/System.Net.Sockets.Tests.csproj
+++ b/src/libraries/System.Net.Sockets/tests/FunctionalTests/System.Net.Sockets.Tests.csproj
@@ -19,7 +19,7 @@
     <Compile Include="DnsEndPointTest.cs" />
     <Compile Include="DualModeSocketTest.cs" />
     <Compile Include="ExecutionContextFlowTest.cs" />
-    <Compile Include="InlineCompletions.Unix.cs" Condition="'$(TargetsUnix)' == 'true'"/>
+    <Compile Include="InlineCompletions.Unix.cs" Condition="'$(TargetPlatformIdentifier)' == 'Unix'"/>
     <Compile Include="IPPacketInformationTest.cs" />
     <Compile Include="KeepAliveTest.cs" />
     <Compile Include="LingerStateTest.cs" />
diff --git a/src/libraries/System.Net.WebClient/ref/System.Net.WebClient.csproj b/src/libraries/System.Net.WebClient/ref/System.Net.WebClient.csproj
index 9174f98458448..732d3211ae524 100644
--- a/src/libraries/System.Net.WebClient/ref/System.Net.WebClient.csproj
+++ b/src/libraries/System.Net.WebClient/ref/System.Net.WebClient.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Net.WebClient/src/System.Net.WebClient.csproj b/src/libraries/System.Net.WebClient/src/System.Net.WebClient.csproj
index 48a1a9c82537c..c317fabee22bd 100644
--- a/src/libraries/System.Net.WebClient/src/System.Net.WebClient.csproj
+++ b/src/libraries/System.Net.WebClient/src/System.Net.WebClient.csproj
@@ -5,9 +5,10 @@
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsBrowser)' == 'true'">SR.SystemNetWebClient_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == 'Browser'">SR.SystemNetWebClient_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsBrowser)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'Browser'">
     <Compile Include="System\Net\WebClient.cs" />
     <Compile Include="$(CommonPath)System\IO\DelegatingStream.cs"
              Link="Common\System\IO\DelegatingStream.cs" />
diff --git a/src/libraries/System.Net.WebHeaderCollection/ref/System.Net.WebHeaderCollection.csproj b/src/libraries/System.Net.WebHeaderCollection/ref/System.Net.WebHeaderCollection.csproj
index f072606731162..6c776532e3676 100644
--- a/src/libraries/System.Net.WebHeaderCollection/ref/System.Net.WebHeaderCollection.csproj
+++ b/src/libraries/System.Net.WebHeaderCollection/ref/System.Net.WebHeaderCollection.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
      <!-- Nullability of parameter 'name' doesn't match overridden member -->
     <NoWarn>$(NoWarn);CS8765</NoWarn>
diff --git a/src/libraries/System.Net.WebHeaderCollection/src/System.Net.WebHeaderCollection.csproj b/src/libraries/System.Net.WebHeaderCollection/src/System.Net.WebHeaderCollection.csproj
index d52760c4c646b..ccec383b56f75 100644
--- a/src/libraries/System.Net.WebHeaderCollection/src/System.Net.WebHeaderCollection.csproj
+++ b/src/libraries/System.Net.WebHeaderCollection/src/System.Net.WebHeaderCollection.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Net.WebProxy/ref/System.Net.WebProxy.csproj b/src/libraries/System.Net.WebProxy/ref/System.Net.WebProxy.csproj
index 43de764895500..7fe0be4f8c5c8 100644
--- a/src/libraries/System.Net.WebProxy/ref/System.Net.WebProxy.csproj
+++ b/src/libraries/System.Net.WebProxy/ref/System.Net.WebProxy.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Net.WebProxy/src/System.Net.WebProxy.csproj b/src/libraries/System.Net.WebProxy/src/System.Net.WebProxy.csproj
index 5fd9532a47b37..e77de26b82c9f 100644
--- a/src/libraries/System.Net.WebProxy/src/System.Net.WebProxy.csproj
+++ b/src/libraries/System.Net.WebProxy/src/System.Net.WebProxy.csproj
@@ -7,8 +7,8 @@
   <ItemGroup>
     <Compile Include="System\Net\IWebProxyScript.cs" />
     <Compile Include="System\Net\WebProxy.cs" />
-    <Compile Condition="'$(TargetsBrowser)' == 'true'" Include="System\Net\WebProxy.Browser.cs" />
-    <Compile Condition="'$(TargetsBrowser)' != 'true'" Include="System\Net\WebProxy.NonBrowser.cs" />
+    <Compile Condition="'$(TargetPlatformIdentifier)' == 'Browser'" Include="System\Net\WebProxy.Browser.cs" />
+    <Compile Condition="'$(TargetPlatformIdentifier)' != 'Browser'" Include="System\Net\WebProxy.NonBrowser.cs" />
   </ItemGroup>
   <ItemGroup>
     <Reference Include="System.Net.NameResolution" />
diff --git a/src/libraries/System.Net.WebSockets.Client/ref/System.Net.WebSockets.Client.csproj b/src/libraries/System.Net.WebSockets.Client/ref/System.Net.WebSockets.Client.csproj
index 7f5666d306484..7793983c080b9 100644
--- a/src/libraries/System.Net.WebSockets.Client/ref/System.Net.WebSockets.Client.csproj
+++ b/src/libraries/System.Net.WebSockets.Client/ref/System.Net.WebSockets.Client.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Net.WebSockets.Client/src/System.Net.WebSockets.Client.csproj b/src/libraries/System.Net.WebSockets.Client/src/System.Net.WebSockets.Client.csproj
index 946ab8f773bdf..79fdea54f1fdd 100644
--- a/src/libraries/System.Net.WebSockets.Client/src/System.Net.WebSockets.Client.csproj
+++ b/src/libraries/System.Net.WebSockets.Client/src/System.Net.WebSockets.Client.csproj
@@ -7,15 +7,15 @@
   <ItemGroup>
     <Compile Include="System\Net\WebSockets\ClientWebSocket.cs" />
     <Compile Include="System\Net\WebSockets\ClientWebSocketDeflateConstants.cs" />
-    <Compile Include="System\Net\WebSockets\ClientWebSocketOptions.cs" Condition="'$(TargetsBrowser)' != 'true'" />
+    <Compile Include="System\Net\WebSockets\ClientWebSocketOptions.cs" Condition="'$(TargetPlatformIdentifier)' != 'Browser'" />
     <Compile Include="$(CommonPath)System\Net\UriScheme.cs" Link="Common\System\Net\UriScheme.cs" />
     <Compile Include="$(CommonPath)System\Net\WebSockets\WebSocketValidate.cs" Link="Common\System\Net\WebSockets\WebSocketValidate.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsBrowser)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'Browser'">
     <Compile Include="System\Net\WebSockets\WebSocketHandle.Managed.cs" />
     <Compile Include="$(CommonPath)System\Net\HttpKnownHeaderNames.cs" Link="Common\System\Net\HttpKnownHeaderNames.cs" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="System\Net\WebSockets\WebSocketHandle.Browser.cs" />
     <Compile Include="System\Net\WebSockets\BrowserWebSockets\BrowserWebSocket.cs" />
     <Compile Include="System\Net\WebSockets\BrowserWebSockets\ClientWebSocketOptions.cs" />
@@ -36,10 +36,10 @@
     <Reference Include="System.Net.Http" />
     <Reference Include="System.Security.Cryptography" />
     <Reference Include="System.Security.Cryptography.Algorithms" />
-    <Reference Include="System.Threading.Channels" Condition="'$(TargetsBrowser)' == 'true'" />
+    <Reference Include="System.Threading.Channels" Condition="'$(TargetPlatformIdentifier)' == 'Browser'" />
     <Reference Include="System.Memory" />
   </ItemGroup>
   <ItemGroup>
-    <ProjectReference Include="$(LibrariesProjectRoot)System.Private.Runtime.InteropServices.JavaScript\src\System.Private.Runtime.InteropServices.JavaScript.csproj" Condition="'$(TargetsBrowser)' == 'true'" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Private.Runtime.InteropServices.JavaScript\src\System.Private.Runtime.InteropServices.JavaScript.csproj" Condition="'$(TargetPlatformIdentifier)' == 'Browser'" />
   </ItemGroup>
 </Project>
diff --git a/src/libraries/System.Net.WebSockets/ref/System.Net.WebSockets.csproj b/src/libraries/System.Net.WebSockets/ref/System.Net.WebSockets.csproj
index 134ea19cd36e5..3f0cf3c821162 100644
--- a/src/libraries/System.Net.WebSockets/ref/System.Net.WebSockets.csproj
+++ b/src/libraries/System.Net.WebSockets/ref/System.Net.WebSockets.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Net.WebSockets/src/System.Net.WebSockets.csproj b/src/libraries/System.Net.WebSockets/src/System.Net.WebSockets.csproj
index 9f2c2cc09cdaf..f19710a066037 100644
--- a/src/libraries/System.Net.WebSockets/src/System.Net.WebSockets.csproj
+++ b/src/libraries/System.Net.WebSockets/src/System.Net.WebSockets.csproj
@@ -36,12 +36,12 @@
              Link="Common\Interop\Interop.zlib.cs" />
   </ItemGroup>
   <!-- Windows specific files -->
-  <ItemGroup Condition=" '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
              Link="Common\Interop\Windows\Interop.Libraries.cs" />
   </ItemGroup>
   <!-- Unix specific files -->
-  <ItemGroup Condition=" '$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true' ">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Browser' ">
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs"
              Link="Common\Interop\Unix\Interop.Libraries.cs" />
   </ItemGroup>
diff --git a/src/libraries/System.Numerics.Vectors/ref/System.Numerics.Vectors.csproj b/src/libraries/System.Numerics.Vectors/ref/System.Numerics.Vectors.csproj
index 42ba04da8db71..05a66d765113a 100644
--- a/src/libraries/System.Numerics.Vectors/ref/System.Numerics.Vectors.csproj
+++ b/src/libraries/System.Numerics.Vectors/ref/System.Numerics.Vectors.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Numerics.Vectors/src/System.Numerics.Vectors.csproj b/src/libraries/System.Numerics.Vectors/src/System.Numerics.Vectors.csproj
index 4f2d15aa3b6a5..a9c43608342de 100644
--- a/src/libraries/System.Numerics.Vectors/src/System.Numerics.Vectors.csproj
+++ b/src/libraries/System.Numerics.Vectors/src/System.Numerics.Vectors.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.ObjectModel/ref/System.ObjectModel.csproj b/src/libraries/System.ObjectModel/ref/System.ObjectModel.csproj
index 623c85ec55670..76645a7f2ed38 100644
--- a/src/libraries/System.ObjectModel/ref/System.ObjectModel.csproj
+++ b/src/libraries/System.ObjectModel/ref/System.ObjectModel.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.ObjectModel/src/System.ObjectModel.csproj b/src/libraries/System.ObjectModel/src/System.ObjectModel.csproj
index ecf4f2a77fe9e..58f389a265912 100644
--- a/src/libraries/System.ObjectModel/src/System.ObjectModel.csproj
+++ b/src/libraries/System.ObjectModel/src/System.ObjectModel.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Private.DataContractSerialization/src/System.Private.DataContractSerialization.csproj b/src/libraries/System.Private.DataContractSerialization/src/System.Private.DataContractSerialization.csproj
index 57474c6e2464b..1e407a2091bc0 100644
--- a/src/libraries/System.Private.DataContractSerialization/src/System.Private.DataContractSerialization.csproj
+++ b/src/libraries/System.Private.DataContractSerialization/src/System.Private.DataContractSerialization.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <NoWarn>$(NoWarn);1634;1691;649</NoWarn>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <!-- Too much private reflection. Do not bother with trimming -->
     <ILLinkTrimAssembly>false</ILLinkTrimAssembly>
     <Nullable>enable</Nullable>
diff --git a/src/libraries/System.Private.Uri/src/System.Private.Uri.csproj b/src/libraries/System.Private.Uri/src/System.Private.Uri.csproj
index ce5a97d87051b..7e19a856a103e 100644
--- a/src/libraries/System.Private.Uri/src/System.Private.Uri.csproj
+++ b/src/libraries/System.Private.Uri/src/System.Private.Uri.csproj
@@ -37,10 +37,10 @@
     <Compile Include="$(CommonPath)System\Text\ValueStringBuilder.cs" Link="Common\System\Text\ValueStringBuilder.cs" />
     <Compile Include="System\ValueStringBuilderExtensions.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\Uri.Windows.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsAnyOS)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == ''">
     <Compile Include="System\Uri.Unix.cs" />
   </ItemGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Private.Xml.Linq/src/System.Private.Xml.Linq.csproj b/src/libraries/System.Private.Xml.Linq/src/System.Private.Xml.Linq.csproj
index a174b927459d7..7c5de0f140e78 100644
--- a/src/libraries/System.Private.Xml.Linq/src/System.Private.Xml.Linq.csproj
+++ b/src/libraries/System.Private.Xml.Linq/src/System.Private.Xml.Linq.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <RootNamespace>System.Xml</RootNamespace>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Private.Xml/src/System.Private.Xml.csproj b/src/libraries/System.Private.Xml/src/System.Private.Xml.csproj
index 613e07f835e94..091753a1dbb92 100644
--- a/src/libraries/System.Private.Xml/src/System.Private.Xml.csproj
+++ b/src/libraries/System.Private.Xml/src/System.Private.Xml.csproj
@@ -779,10 +779,10 @@
     <Compile Include="System\Xml\Core\LocalAppContextSwitches.cs" />
     <Compile Include="$(CommonPath)System\CSharpHelpers.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)'=='true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\Xml\Xsl\Runtime\XmlCollation.Windows.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsAnyOS)'=='true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == ''">
     <Compile Include="System\Xml\Xsl\Runtime\XmlCollation.Unix.cs" />
     <Compile Include="System\Xml\Core\XmlTextReaderImpl.Unix.cs" />
   </ItemGroup>
diff --git a/src/libraries/System.Reflection.DispatchProxy/ref/System.Reflection.DispatchProxy.csproj b/src/libraries/System.Reflection.DispatchProxy/ref/System.Reflection.DispatchProxy.csproj
index 2759e12af1204..6039cbc7d5e26 100644
--- a/src/libraries/System.Reflection.DispatchProxy/ref/System.Reflection.DispatchProxy.csproj
+++ b/src/libraries/System.Reflection.DispatchProxy/ref/System.Reflection.DispatchProxy.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Reflection.DispatchProxy/src/System.Reflection.DispatchProxy.csproj b/src/libraries/System.Reflection.DispatchProxy/src/System.Reflection.DispatchProxy.csproj
index babd7f14e4ed6..4fd66210d47ef 100644
--- a/src/libraries/System.Reflection.DispatchProxy/src/System.Reflection.DispatchProxy.csproj
+++ b/src/libraries/System.Reflection.DispatchProxy/src/System.Reflection.DispatchProxy.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Reflection.Emit.ILGeneration/ref/System.Reflection.Emit.ILGeneration.csproj b/src/libraries/System.Reflection.Emit.ILGeneration/ref/System.Reflection.Emit.ILGeneration.csproj
index 48837d6105f25..709b299efec00 100644
--- a/src/libraries/System.Reflection.Emit.ILGeneration/ref/System.Reflection.Emit.ILGeneration.csproj
+++ b/src/libraries/System.Reflection.Emit.ILGeneration/ref/System.Reflection.Emit.ILGeneration.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Reflection.Emit.ILGeneration/src/System.Reflection.Emit.ILGeneration.csproj b/src/libraries/System.Reflection.Emit.ILGeneration/src/System.Reflection.Emit.ILGeneration.csproj
index 4f2d15aa3b6a5..a9c43608342de 100644
--- a/src/libraries/System.Reflection.Emit.ILGeneration/src/System.Reflection.Emit.ILGeneration.csproj
+++ b/src/libraries/System.Reflection.Emit.ILGeneration/src/System.Reflection.Emit.ILGeneration.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Reflection.Emit.Lightweight/ref/System.Reflection.Emit.Lightweight.csproj b/src/libraries/System.Reflection.Emit.Lightweight/ref/System.Reflection.Emit.Lightweight.csproj
index f5ee53a8ae064..5c26ae3990a1e 100644
--- a/src/libraries/System.Reflection.Emit.Lightweight/ref/System.Reflection.Emit.Lightweight.csproj
+++ b/src/libraries/System.Reflection.Emit.Lightweight/ref/System.Reflection.Emit.Lightweight.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <Nullable>enable</Nullable>
   </PropertyGroup>
diff --git a/src/libraries/System.Reflection.Emit.Lightweight/src/System.Reflection.Emit.Lightweight.csproj b/src/libraries/System.Reflection.Emit.Lightweight/src/System.Reflection.Emit.Lightweight.csproj
index 4f2d15aa3b6a5..a9c43608342de 100644
--- a/src/libraries/System.Reflection.Emit.Lightweight/src/System.Reflection.Emit.Lightweight.csproj
+++ b/src/libraries/System.Reflection.Emit.Lightweight/src/System.Reflection.Emit.Lightweight.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Reflection.Emit/ref/System.Reflection.Emit.csproj b/src/libraries/System.Reflection.Emit/ref/System.Reflection.Emit.csproj
index be3da7e142922..69f55b0c9a693 100644
--- a/src/libraries/System.Reflection.Emit/ref/System.Reflection.Emit.csproj
+++ b/src/libraries/System.Reflection.Emit/ref/System.Reflection.Emit.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Reflection.Emit/src/System.Reflection.Emit.csproj b/src/libraries/System.Reflection.Emit/src/System.Reflection.Emit.csproj
index 4f2d15aa3b6a5..a9c43608342de 100644
--- a/src/libraries/System.Reflection.Emit/src/System.Reflection.Emit.csproj
+++ b/src/libraries/System.Reflection.Emit/src/System.Reflection.Emit.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Reflection.Extensions/ref/System.Reflection.Extensions.csproj b/src/libraries/System.Reflection.Extensions/ref/System.Reflection.Extensions.csproj
index ac1351c0752b8..fc9bd6eb7bd6d 100644
--- a/src/libraries/System.Reflection.Extensions/ref/System.Reflection.Extensions.csproj
+++ b/src/libraries/System.Reflection.Extensions/ref/System.Reflection.Extensions.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Reflection.Extensions/src/System.Reflection.Extensions.csproj b/src/libraries/System.Reflection.Extensions/src/System.Reflection.Extensions.csproj
index 94d0c64013048..36c7cb1bdde2a 100644
--- a/src/libraries/System.Reflection.Extensions/src/System.Reflection.Extensions.csproj
+++ b/src/libraries/System.Reflection.Extensions/src/System.Reflection.Extensions.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Reflection.Primitives/ref/System.Reflection.Primitives.csproj b/src/libraries/System.Reflection.Primitives/ref/System.Reflection.Primitives.csproj
index 9d2d488b8cc11..2902a67fdf076 100644
--- a/src/libraries/System.Reflection.Primitives/ref/System.Reflection.Primitives.csproj
+++ b/src/libraries/System.Reflection.Primitives/ref/System.Reflection.Primitives.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Reflection.Primitives/src/System.Reflection.Primitives.csproj b/src/libraries/System.Reflection.Primitives/src/System.Reflection.Primitives.csproj
index dd3dc2940a54b..5ecfe239de6f7 100644
--- a/src/libraries/System.Reflection.Primitives/src/System.Reflection.Primitives.csproj
+++ b/src/libraries/System.Reflection.Primitives/src/System.Reflection.Primitives.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Reflection.TypeExtensions/ref/System.Reflection.TypeExtensions.csproj b/src/libraries/System.Reflection.TypeExtensions/ref/System.Reflection.TypeExtensions.csproj
index 5463928fbaf07..b2a838b7f814e 100644
--- a/src/libraries/System.Reflection.TypeExtensions/ref/System.Reflection.TypeExtensions.csproj
+++ b/src/libraries/System.Reflection.TypeExtensions/ref/System.Reflection.TypeExtensions.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <Nullable>enable</Nullable>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System.Reflection.TypeExtensions.cs" />
diff --git a/src/libraries/System.Reflection.TypeExtensions/src/System.Reflection.TypeExtensions.csproj b/src/libraries/System.Reflection.TypeExtensions/src/System.Reflection.TypeExtensions.csproj
index e078dd282ebe7..e000ddd696ce7 100644
--- a/src/libraries/System.Reflection.TypeExtensions/src/System.Reflection.TypeExtensions.csproj
+++ b/src/libraries/System.Reflection.TypeExtensions/src/System.Reflection.TypeExtensions.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
     <Nullable>enable</Nullable>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System\Reflection\TypeExtensions.cs" />
diff --git a/src/libraries/System.Reflection/ref/System.Reflection.csproj b/src/libraries/System.Reflection/ref/System.Reflection.csproj
index 61b26cc370d89..721d268bc5693 100644
--- a/src/libraries/System.Reflection/ref/System.Reflection.csproj
+++ b/src/libraries/System.Reflection/ref/System.Reflection.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Reflection/src/System.Reflection.csproj b/src/libraries/System.Reflection/src/System.Reflection.csproj
index 4f2d15aa3b6a5..a9c43608342de 100644
--- a/src/libraries/System.Reflection/src/System.Reflection.csproj
+++ b/src/libraries/System.Reflection/src/System.Reflection.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Resources.Extensions/tests/System.Resources.Extensions.Tests.csproj b/src/libraries/System.Resources.Extensions/tests/System.Resources.Extensions.Tests.csproj
index dc2bb32692ebe..ad289dc63190c 100644
--- a/src/libraries/System.Resources.Extensions/tests/System.Resources.Extensions.Tests.csproj
+++ b/src/libraries/System.Resources.Extensions/tests/System.Resources.Extensions.Tests.csproj
@@ -20,7 +20,7 @@
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp'">
     <ProjectReference Include="$(LibrariesProjectRoot)System.Drawing.Common\src\System.Drawing.Common.csproj" />
-    <ProjectReference Include="$(LibrariesProjectRoot)System.Windows.Extensions\src\System.Windows.Extensions.csproj" Condition="'$(TargetsWindows)' == 'true'" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Windows.Extensions\src\System.Windows.Extensions.csproj" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework'">
     <PackageReference Include="System.ValueTuple" Version="$(SystemValueTupleVersion)" />
diff --git a/src/libraries/System.Resources.Reader/ref/System.Resources.Reader.csproj b/src/libraries/System.Resources.Reader/ref/System.Resources.Reader.csproj
index a58632790d72a..ac31c124d77d6 100644
--- a/src/libraries/System.Resources.Reader/ref/System.Resources.Reader.csproj
+++ b/src/libraries/System.Resources.Reader/ref/System.Resources.Reader.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Resources.Reader/src/System.Resources.Reader.csproj b/src/libraries/System.Resources.Reader/src/System.Resources.Reader.csproj
index 81ff3cda55d88..1a509db46e814 100644
--- a/src/libraries/System.Resources.Reader/src/System.Resources.Reader.csproj
+++ b/src/libraries/System.Resources.Reader/src/System.Resources.Reader.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <RootNamespace>System.Resources</RootNamespace>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Resources.ResourceManager/ref/System.Resources.ResourceManager.csproj b/src/libraries/System.Resources.ResourceManager/ref/System.Resources.ResourceManager.csproj
index a1367c6a97a11..7bfbabc81984b 100644
--- a/src/libraries/System.Resources.ResourceManager/ref/System.Resources.ResourceManager.csproj
+++ b/src/libraries/System.Resources.ResourceManager/ref/System.Resources.ResourceManager.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Resources.ResourceManager/src/System.Resources.ResourceManager.csproj b/src/libraries/System.Resources.ResourceManager/src/System.Resources.ResourceManager.csproj
index 4f2d15aa3b6a5..a9c43608342de 100644
--- a/src/libraries/System.Resources.ResourceManager/src/System.Resources.ResourceManager.csproj
+++ b/src/libraries/System.Resources.ResourceManager/src/System.Resources.ResourceManager.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Resources.Writer/ref/System.Resources.Writer.csproj b/src/libraries/System.Resources.Writer/ref/System.Resources.Writer.csproj
index 5d9d0ee9332d6..89d629821c6ef 100644
--- a/src/libraries/System.Resources.Writer/ref/System.Resources.Writer.csproj
+++ b/src/libraries/System.Resources.Writer/ref/System.Resources.Writer.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <Nullable>enable</Nullable>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System.Resources.Writer.cs" />
diff --git a/src/libraries/System.Resources.Writer/src/System.Resources.Writer.csproj b/src/libraries/System.Resources.Writer/src/System.Resources.Writer.csproj
index b910ab24e06a6..b476784344b6b 100644
--- a/src/libraries/System.Resources.Writer/src/System.Resources.Writer.csproj
+++ b/src/libraries/System.Resources.Writer/src/System.Resources.Writer.csproj
@@ -3,7 +3,7 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <RootNamespace>System.Resources</RootNamespace>
     <Nullable>enable</Nullable>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System\Resources\__FastResourceComparer.cs" />
diff --git a/src/libraries/System.Runtime.Caching/src/System.Runtime.Caching.csproj b/src/libraries/System.Runtime.Caching/src/System.Runtime.Caching.csproj
index a567a23967c5d..a9da990b9c9dd 100644
--- a/src/libraries/System.Runtime.Caching/src/System.Runtime.Caching.csproj
+++ b/src/libraries/System.Runtime.Caching/src/System.Runtime.Caching.csproj
@@ -66,7 +66,7 @@ System.Runtime.Caching.ObjectCache</PackageDescription>
     <Compile Include="System\Runtime\Caching\Hosting\IMemoryCacheManager.cs" />
     <Compile Include="System\Runtime\Caching\Resources\RH.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\Runtime\Caching\MemoryMonitor.Windows.cs" />
     <Compile Include="System\Runtime\Caching\PhysicalMemoryMonitor.Windows.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.BOOL.cs" Link="Common\Interop\Windows\Interop.BOOL.cs" />
@@ -74,7 +74,7 @@ System.Runtime.Caching.ObjectCache</PackageDescription>
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.MEMORYSTATUSEX.cs" Link="Common\Interop\Windows\Kernel32\Interop.MEMORYSTATUSEX.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs" Link="Common\Interop\Windows\Interop.Libraries.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'windows'">
     <Compile Include="System\Runtime\Caching\PhysicalMemoryMonitor.Unix.cs" />
   </ItemGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Runtime.CompilerServices.VisualC/ref/System.Runtime.CompilerServices.VisualC.csproj b/src/libraries/System.Runtime.CompilerServices.VisualC/ref/System.Runtime.CompilerServices.VisualC.csproj
index c63584df9a6fa..a4367378e73fd 100644
--- a/src/libraries/System.Runtime.CompilerServices.VisualC/ref/System.Runtime.CompilerServices.VisualC.csproj
+++ b/src/libraries/System.Runtime.CompilerServices.VisualC/ref/System.Runtime.CompilerServices.VisualC.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <Nullable>enable</Nullable>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System.Runtime.CompilerServices.VisualC.cs" />
diff --git a/src/libraries/System.Runtime.CompilerServices.VisualC/src/System.Runtime.CompilerServices.VisualC.csproj b/src/libraries/System.Runtime.CompilerServices.VisualC/src/System.Runtime.CompilerServices.VisualC.csproj
index d0ca0d4c3203d..e870ee097993f 100644
--- a/src/libraries/System.Runtime.CompilerServices.VisualC/src/System.Runtime.CompilerServices.VisualC.csproj
+++ b/src/libraries/System.Runtime.CompilerServices.VisualC/src/System.Runtime.CompilerServices.VisualC.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <Nullable>enable</Nullable>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <!-- Shared CoreCLR -->
   <ItemGroup>
diff --git a/src/libraries/System.Runtime.Experimental/ref/System.Runtime.Experimental.csproj b/src/libraries/System.Runtime.Experimental/ref/System.Runtime.Experimental.csproj
index 7114edf7757f1..f229a1681202d 100644
--- a/src/libraries/System.Runtime.Experimental/ref/System.Runtime.Experimental.csproj
+++ b/src/libraries/System.Runtime.Experimental/ref/System.Runtime.Experimental.csproj
@@ -9,7 +9,7 @@
         Remove warning disable when nullable attributes are respected,
         Type has no accessible constructors which use only CLS-compliant types -->
     <NoWarn>$(NoWarn);0809;0618;CS8614;CS3015;NU5131</NoWarn>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <PropertyGroup Condition="'$(FeatureGenericMath)' == 'true'">
diff --git a/src/libraries/System.Runtime.Extensions/ref/System.Runtime.Extensions.csproj b/src/libraries/System.Runtime.Extensions/ref/System.Runtime.Extensions.csproj
index 32152c73ed4d0..23001b05b96ff 100644
--- a/src/libraries/System.Runtime.Extensions/ref/System.Runtime.Extensions.csproj
+++ b/src/libraries/System.Runtime.Extensions/ref/System.Runtime.Extensions.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <NoWarn>$(NoWarn);CS0618</NoWarn>
     <Nullable>enable</Nullable>
   </PropertyGroup>
diff --git a/src/libraries/System.Runtime.Extensions/src/System.Runtime.Extensions.csproj b/src/libraries/System.Runtime.Extensions/src/System.Runtime.Extensions.csproj
index b6029a4baee65..748322734e2cf 100644
--- a/src/libraries/System.Runtime.Extensions/src/System.Runtime.Extensions.csproj
+++ b/src/libraries/System.Runtime.Extensions/src/System.Runtime.Extensions.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Runtime.Extensions/tests/System.Runtime.Extensions.Tests.csproj b/src/libraries/System.Runtime.Extensions/tests/System.Runtime.Extensions.Tests.csproj
index 71788c421b44e..9574f7d433c48 100644
--- a/src/libraries/System.Runtime.Extensions/tests/System.Runtime.Extensions.Tests.csproj
+++ b/src/libraries/System.Runtime.Extensions/tests/System.Runtime.Extensions.Tests.csproj
@@ -1,12 +1,16 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <DefineConstants Condition="'$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true'">$(DefineConstants);Unix</DefineConstants>
     <TestRuntime>true</TestRuntime>
     <IncludeRemoteExecutor>true</IncludeRemoteExecutor>
     <EnableDllImportGenerator>true</EnableDllImportGenerator>
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent)-Browser</TargetFrameworks>
   </PropertyGroup>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
+  <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Browser'">$(DefineConstants);Unix</DefineConstants>
+  </PropertyGroup>
   <ItemGroup>
     <Compile Include="System\ApplicationIdTests.cs" />
     <Compile Include="System\Convert.cs" />
@@ -76,7 +80,7 @@
     <Compile Include="System\Runtime\ProfileOptimization.cs" />
     <Compile Include="System\Runtime\CompilerServices\SwitchExpressionExceptionTests.cs" />
 
-    <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.GetHostName.cs" Condition="'$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true'" Link="Common\Interop\Unix\System.Native\Interop.GetHostName.cs" />
+    <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.GetHostName.cs" Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Browser'" Link="Common\Interop\Unix\System.Native\Interop.GetHostName.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs" Link="Common\Interop\Unix\Interop.Libraries.cs" />
     <Compile Include="$(CommonTestPath)System\IO\PathFeatures.cs" Link="Common\System\IO\PathFeatures.cs" />
     <Compile Include="$(CommonTestPath)System\ShouldNotBeInvokedException.cs" Link="Common\System\ShouldNotBeInvokedException.cs" />
diff --git a/src/libraries/System.Runtime.Handles/ref/System.Runtime.Handles.csproj b/src/libraries/System.Runtime.Handles/ref/System.Runtime.Handles.csproj
index 87bea6d58fdc2..39ab002c1e77b 100644
--- a/src/libraries/System.Runtime.Handles/ref/System.Runtime.Handles.csproj
+++ b/src/libraries/System.Runtime.Handles/ref/System.Runtime.Handles.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Runtime.Handles/src/System.Runtime.Handles.csproj b/src/libraries/System.Runtime.Handles/src/System.Runtime.Handles.csproj
index 94d0c64013048..36c7cb1bdde2a 100644
--- a/src/libraries/System.Runtime.Handles/src/System.Runtime.Handles.csproj
+++ b/src/libraries/System.Runtime.Handles/src/System.Runtime.Handles.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Runtime.InteropServices.RuntimeInformation/ref/System.Runtime.InteropServices.RuntimeInformation.csproj b/src/libraries/System.Runtime.InteropServices.RuntimeInformation/ref/System.Runtime.InteropServices.RuntimeInformation.csproj
index f752541dd4440..6a61700686d61 100644
--- a/src/libraries/System.Runtime.InteropServices.RuntimeInformation/ref/System.Runtime.InteropServices.RuntimeInformation.csproj
+++ b/src/libraries/System.Runtime.InteropServices.RuntimeInformation/ref/System.Runtime.InteropServices.RuntimeInformation.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <Nullable>enable</Nullable>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System.Runtime.InteropServices.RuntimeInformation.Forwards.cs" />
diff --git a/src/libraries/System.Runtime.InteropServices.RuntimeInformation/src/System.Runtime.InteropServices.RuntimeInformation.csproj b/src/libraries/System.Runtime.InteropServices.RuntimeInformation/src/System.Runtime.InteropServices.RuntimeInformation.csproj
index 94d0c64013048..36c7cb1bdde2a 100644
--- a/src/libraries/System.Runtime.InteropServices.RuntimeInformation/src/System.Runtime.InteropServices.RuntimeInformation.csproj
+++ b/src/libraries/System.Runtime.InteropServices.RuntimeInformation/src/System.Runtime.InteropServices.RuntimeInformation.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Runtime.InteropServices/ref/System.Runtime.InteropServices.csproj b/src/libraries/System.Runtime.InteropServices/ref/System.Runtime.InteropServices.csproj
index f2533619f265f..c7219439445e2 100644
--- a/src/libraries/System.Runtime.InteropServices/ref/System.Runtime.InteropServices.csproj
+++ b/src/libraries/System.Runtime.InteropServices/ref/System.Runtime.InteropServices.csproj
@@ -5,7 +5,7 @@
     <!-- Nullability of parameter 'name' doesn't match overridden member -->
     <NoWarn>$(NoWarn);618;CS8765</NoWarn>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Runtime.InteropServices/src/System.Runtime.InteropServices.csproj b/src/libraries/System.Runtime.InteropServices/src/System.Runtime.InteropServices.csproj
index 3bc59997f7f0c..49ebaf784dc66 100644
--- a/src/libraries/System.Runtime.InteropServices/src/System.Runtime.InteropServices.csproj
+++ b/src/libraries/System.Runtime.InteropServices/src/System.Runtime.InteropServices.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
     <Nullable>enable</Nullable>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System\Runtime\CompilerServices\IDispatchConstantAttribute.cs" />
diff --git a/src/libraries/System.Runtime.InteropServices/tests/System.Runtime.InteropServices.UnitTests/System.Runtime.InteropServices.Tests.csproj b/src/libraries/System.Runtime.InteropServices/tests/System.Runtime.InteropServices.UnitTests/System.Runtime.InteropServices.Tests.csproj
index 4dc5e6b435091..072080790a255 100644
--- a/src/libraries/System.Runtime.InteropServices/tests/System.Runtime.InteropServices.UnitTests/System.Runtime.InteropServices.Tests.csproj
+++ b/src/libraries/System.Runtime.InteropServices/tests/System.Runtime.InteropServices.UnitTests/System.Runtime.InteropServices.Tests.csproj
@@ -22,7 +22,7 @@
     <Compile Include="System\Runtime\InteropServices\CollectionsMarshalTests.cs" />
     <Compile Include="System\Runtime\InteropServices\ComAliasNameAttributeTests.cs" />
     <Compile Include="System\Runtime\InteropServices\ComAwareEventInfoTests.cs" />
-    <Compile Include="System\Runtime\InteropServices\ComAwareEventInfoTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\ComAwareEventInfoTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\ComCompatibleVersionAttributeTests.cs" />
     <Compile Include="System\Runtime\InteropServices\ComConversionLossAttributeTests.cs" />
     <Compile Include="System\Runtime\InteropServices\ComDefaultInterfaceAttributeTests.cs" />
@@ -61,47 +61,47 @@
     <Compile Include="System\Runtime\InteropServices\Marshal\AllocHGlobalTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\BindToMonikerTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\ChangeWrapperHandleStrengthTests.cs" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\ChangeWrapperHandleStrengthTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\ChangeWrapperHandleStrengthTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\Marshal\CreateAggregatedObjectTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\CreateWrapperOfTypeTests.cs" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\CreateWrapperOfTypeTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\CreateWrapperOfTypeTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\Marshal\DestroyStructureTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\FinalReleaseComObjectTests.cs" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\FinalReleaseComObjectTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\FinalReleaseComObjectTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\Marshal\FreeBSTRTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\FreeCoTaskMemTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\FreeHGlobalTests.cs" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\GenerateGuidForTypeTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\GenerateProgIdForTypeTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\GenerateGuidForTypeTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\GenerateProgIdForTypeTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetComInterfaceForObjectTests.cs" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\GetComObjectDataTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\GetComObjectDataTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetDelegateForFunctionPointerTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetExceptionCodeTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetExceptionForHRTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetFunctionPointerForDelegateTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetHRForExceptionTests.cs" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\GetIDispatchForObjectTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\GetIDispatchForObjectTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetIUnknownForObjectTests.cs" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\GetNativeVariantForObjectTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\GetNativeVariantForObjectTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetNativeVariantForObjectTests.cs" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\GetObjectForIUnknownTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\GetObjectForIUnknownTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetObjectForIUnknownTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetObjectForNativeVariantTests.cs" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\GetObjectForNativeVariantTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\GetObjectForNativeVariantTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetObjectsForNativeVariantsTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetStartComSlotTests.cs" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\GetStartComSlotTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\GetStartComSlotTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetTypeFromCLSIDTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetTypeInfoNameTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetUniqueObjectForIUnknownTests.cs" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\GetUniqueObjectForIUnknownTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\GetUniqueObjectForIUnknownTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\Marshal\InitHandleTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\IsComObjectTests.cs" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\IsComObjectTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\IsComObjectTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\Marshal\LastErrorTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\ReleaseTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\ReleaseComObjectTests.cs" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\ReleaseComObjectTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\ReleaseComObjectTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\Marshal\PtrToStructureTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\PtrToStringAnsiTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\PtrToStringAutoTests.cs" />
@@ -109,7 +109,7 @@
     <Compile Include="System\Runtime\InteropServices\Marshal\PtrToStringUniTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\PtrToStringUTF8Tests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\QueryInterfaceTests.cs" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\QueryInterfaceTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\QueryInterfaceTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\Marshal\ReAllocHGlobalTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\ReAllocCoTaskMemTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\SecureStringToBSTRTests.cs" />
@@ -117,7 +117,7 @@
     <Compile Include="System\Runtime\InteropServices\Marshal\SecureStringToCoTaskMemUnicodeTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\SecureStringToGlobalAllocAnsiTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\SecureStringToGlobalAllocUnicodeTests.cs" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\SetComObjectDataTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\SetComObjectDataTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\Marshal\SizeOfTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\StringToBSTRTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\StringToCoTaskMemAnsiTests.cs" />
@@ -138,7 +138,7 @@
     <Compile Include="System\Runtime\InteropServices\Marshal\ZeroFreeGlobalAllocUnicodeTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\Common\CommonTypes.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\Common\COMWrappersImpl.cs" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\Common\CommonTypes.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\Common\CommonTypes.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\Marshal\Common\Variant.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\ReadWrite\ByteTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\ReadWrite\Int16Tests.cs" />
@@ -171,14 +171,14 @@
     <Compile Include="System\Runtime\InteropServices\Marshal\GenerateProgIdForTypeTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetComObjectDataTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetEndComSlotTests.cs" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\GetEndComSlotTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\GetEndComSlotTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetExceptionPointersTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetHINSTANCETests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetIDispatchForObjectTests.cs" />
     <Compile Include="System\Runtime\InteropServices\Marshal\GetTypedObjectForIUnknownTests.cs" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\GetTypedObjectForIUnknownTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\GetTypedObjectForIUnknownTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\Marshal\IsTypeVisibleFromComTests.cs" />
-    <Compile Include="System\Runtime\InteropServices\Marshal\IsTypeVisibleFromComTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="System\Runtime\InteropServices\Marshal\IsTypeVisibleFromComTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="System\Runtime\InteropServices\Marshal\SetComObjectDataTests.cs" />
     <Compile Include="System\Runtime\InteropServices\TypeLibFuncAttributeTests.cs" />
     <Compile Include="System\Runtime\InteropServices\TypeLibImportClassAttributeTests.cs" />
@@ -186,10 +186,10 @@
     <Compile Include="System\Runtime\InteropServices\TypeLibVarAttributeTests.cs" />
     <Compile Include="System\Runtime\InteropServices\TypeLibVersionAttributeTests.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\Runtime\InteropServices\PosixSignalRegistrationTests.Windows.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="System\Runtime\InteropServices\PosixSignalRegistrationTests.Unix.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs" Link="Common\Interop\Unix\Interop.Libraries.cs" />
   </ItemGroup>
diff --git a/src/libraries/System.Runtime.Intrinsics/ref/System.Runtime.Intrinsics.csproj b/src/libraries/System.Runtime.Intrinsics/ref/System.Runtime.Intrinsics.csproj
index 99d42572c65e5..a2f37c85cd403 100644
--- a/src/libraries/System.Runtime.Intrinsics/ref/System.Runtime.Intrinsics.csproj
+++ b/src/libraries/System.Runtime.Intrinsics/ref/System.Runtime.Intrinsics.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Runtime.Intrinsics/src/System.Runtime.Intrinsics.csproj b/src/libraries/System.Runtime.Intrinsics/src/System.Runtime.Intrinsics.csproj
index dd3dc2940a54b..5ecfe239de6f7 100644
--- a/src/libraries/System.Runtime.Intrinsics/src/System.Runtime.Intrinsics.csproj
+++ b/src/libraries/System.Runtime.Intrinsics/src/System.Runtime.Intrinsics.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Runtime.Loader/ref/System.Runtime.Loader.csproj b/src/libraries/System.Runtime.Loader/ref/System.Runtime.Loader.csproj
index f167ed3e9ded8..92bc3b365e068 100644
--- a/src/libraries/System.Runtime.Loader/ref/System.Runtime.Loader.csproj
+++ b/src/libraries/System.Runtime.Loader/ref/System.Runtime.Loader.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Runtime.Loader/src/System.Runtime.Loader.csproj b/src/libraries/System.Runtime.Loader/src/System.Runtime.Loader.csproj
index dd3dc2940a54b..5ecfe239de6f7 100644
--- a/src/libraries/System.Runtime.Loader/src/System.Runtime.Loader.csproj
+++ b/src/libraries/System.Runtime.Loader/src/System.Runtime.Loader.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Runtime.Numerics/ref/System.Runtime.Numerics.csproj b/src/libraries/System.Runtime.Numerics/ref/System.Runtime.Numerics.csproj
index 39e712be0627a..03c9a9dd37e27 100644
--- a/src/libraries/System.Runtime.Numerics/ref/System.Runtime.Numerics.csproj
+++ b/src/libraries/System.Runtime.Numerics/ref/System.Runtime.Numerics.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <Nullable>enable</Nullable>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System.Runtime.Numerics.cs" />
diff --git a/src/libraries/System.Runtime.Numerics/src/System.Runtime.Numerics.csproj b/src/libraries/System.Runtime.Numerics/src/System.Runtime.Numerics.csproj
index d61ea2546b168..5c2f63834c360 100644
--- a/src/libraries/System.Runtime.Numerics/src/System.Runtime.Numerics.csproj
+++ b/src/libraries/System.Runtime.Numerics/src/System.Runtime.Numerics.csproj
@@ -3,7 +3,7 @@
     <RootNamespace>System.Numerics</RootNamespace>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <Nullable>enable</Nullable>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System\Numerics\BigIntegerCalculator.AddSub.cs" />
diff --git a/src/libraries/System.Runtime.Serialization.Formatters/ref/System.Runtime.Serialization.Formatters.csproj b/src/libraries/System.Runtime.Serialization.Formatters/ref/System.Runtime.Serialization.Formatters.csproj
index 20657fa0322d0..c3192c2662a1d 100644
--- a/src/libraries/System.Runtime.Serialization.Formatters/ref/System.Runtime.Serialization.Formatters.csproj
+++ b/src/libraries/System.Runtime.Serialization.Formatters/ref/System.Runtime.Serialization.Formatters.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Runtime.Serialization.Formatters/src/System.Runtime.Serialization.Formatters.csproj b/src/libraries/System.Runtime.Serialization.Formatters/src/System.Runtime.Serialization.Formatters.csproj
index 137d1e55d6af8..45a2328010937 100644
--- a/src/libraries/System.Runtime.Serialization.Formatters/src/System.Runtime.Serialization.Formatters.csproj
+++ b/src/libraries/System.Runtime.Serialization.Formatters/src/System.Runtime.Serialization.Formatters.csproj
@@ -1,16 +1,18 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent);$(NetCoreAppCurrent)-Browser;$(NetCoreAppCurrent)-iOS;$(NetCoreAppCurrent)-tvOS;$(NetCoreAppCurrent)-Android;</TargetFrameworks>
+    <TargetFrameworks>$(NetCoreAppCurrent);$(NetCoreAppCurrent)-Browser;$(NetCoreAppCurrent)-iOS;$(NetCoreAppCurrent)-tvOS;$(NetCoreAppCurrent)-Android</TargetFrameworks>
     <Nullable>enable</Nullable>
-    <!-- When we replace implementations with PNSE, need to suppress some "field is never assigned to" warnings. -->
-    <NoWarn Condition="'$(TargetsMobile)' == 'true'">$(NoWarn);CS0649</NoWarn>
+    <!-- ILLinker settings -->
+    <ILLinkDirectory>$(MSBuildThisFileDirectory)ILLink\</ILLinkDirectory>
   </PropertyGroup>
-  <!-- ILLinker settings -->
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <ILLinkDirectory>$(MSBuildThisFileDirectory)ILLink\</ILLinkDirectory>
+    <TargetPlatformIdentifier Condition="$(TargetFramework.Contains('-'))">$(TargetFramework.SubString($([MSBuild]::Add($(TargetFramework.IndexOf('-')), 1))))</TargetPlatformIdentifier>
+    <!-- TargetsMobile: When we replace implementations with PNSE, need to suppress some "field is never assigned to" warnings. -->
+    <NoWarn Condition="'$(TargetPlatformIdentifier)' != ''">$(NoWarn);CS0649</NoWarn>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsMobile)' != 'true'">
-    <ILLinkSubstitutionsXmls Include="$(ILLinkDirectory)ILLink.Substitutions.NonMobile.xml" />
+  <ItemGroup>
+    <ILLinkSubstitutionsXmls Condition="'$(TargetPlatformIdentifier)' == ''" Include="$(ILLinkDirectory)ILLink.Substitutions.NonMobile.xml" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="System.Runtime.Serialization.Formatters.TypeForwards.cs" />
@@ -67,14 +69,14 @@
     <Compile Include="$(CoreLibSharedDir)System\Collections\HashHelpers.cs"
              Link="Common\System\Collections\HashHelpers.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsMobile)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == ''">
     <Compile Include="System\Runtime\Serialization\Formatters\Binary\BinaryFormatter.Core.cs" />
     <Compile Include="System\Runtime\Serialization\LocalAppContextSwitches.cs" />
     <Compile Include="$(CommonPath)System\LocalAppContextSwitches.Common.cs">
       <Link>Common\System\LocalAppContextSwitches.Common.cs</Link>
     </Compile>
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsMobile)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="System\Runtime\Serialization\Formatters\Binary\BinaryFormatter.PlatformNotSupported.cs" />
   </ItemGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Runtime.Serialization.Formatters/tests/System.Runtime.Serialization.Formatters.Tests.csproj b/src/libraries/System.Runtime.Serialization.Formatters/tests/System.Runtime.Serialization.Formatters.Tests.csproj
index 0974cc86d7d3f..bb5a72a9fd280 100644
--- a/src/libraries/System.Runtime.Serialization.Formatters/tests/System.Runtime.Serialization.Formatters.Tests.csproj
+++ b/src/libraries/System.Runtime.Serialization.Formatters/tests/System.Runtime.Serialization.Formatters.Tests.csproj
@@ -12,7 +12,7 @@
     <Compile Include="OptionalFieldAttributeTests.cs" />
     <Compile Include="FormatterConverterTests.cs" />
     <Compile Include="FormatterServicesTests.cs" />
-    <Compile Include="FormatterServicesTests.Windows.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="FormatterServicesTests.Windows.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="FormatterTests.cs" />
     <Compile Include="PlatformExtensions.cs" />
     <Compile Include="SerializationBinderTests.cs" />
@@ -28,7 +28,7 @@
     <Compile Include="$(CommonTestPath)System\Runtime\Serialization\Formatters\BinaryFormatterHelpers.cs"
              Link="Common\System\Runtime\Serialization\Formatters\BinaryFormatterHelpers.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetFramework)' == 'net48'">
+  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework'">
     <Compile Include="$(CommonPath)System\Collections\Generic\ReferenceEqualityComparer.cs"
              Link="Common\System\Collections\Generic\ReferenceEqualityComparer.cs" />
   </ItemGroup>
diff --git a/src/libraries/System.Runtime.Serialization.Json/ref/System.Runtime.Serialization.Json.csproj b/src/libraries/System.Runtime.Serialization.Json/ref/System.Runtime.Serialization.Json.csproj
index a25d7b6d5c157..8f1c520afdcba 100644
--- a/src/libraries/System.Runtime.Serialization.Json/ref/System.Runtime.Serialization.Json.csproj
+++ b/src/libraries/System.Runtime.Serialization.Json/ref/System.Runtime.Serialization.Json.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Runtime.Serialization.Json/src/System.Runtime.Serialization.Json.csproj b/src/libraries/System.Runtime.Serialization.Json/src/System.Runtime.Serialization.Json.csproj
index 9cdaf74ee951e..0ad2fb06652cd 100644
--- a/src/libraries/System.Runtime.Serialization.Json/src/System.Runtime.Serialization.Json.csproj
+++ b/src/libraries/System.Runtime.Serialization.Json/src/System.Runtime.Serialization.Json.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Runtime.Serialization.Primitives/ref/System.Runtime.Serialization.Primitives.csproj b/src/libraries/System.Runtime.Serialization.Primitives/ref/System.Runtime.Serialization.Primitives.csproj
index bcb2151821ac8..065dfb3ceb957 100644
--- a/src/libraries/System.Runtime.Serialization.Primitives/ref/System.Runtime.Serialization.Primitives.csproj
+++ b/src/libraries/System.Runtime.Serialization.Primitives/ref/System.Runtime.Serialization.Primitives.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <Nullable>enable</Nullable>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System.Runtime.Serialization.Primitives.cs" />
diff --git a/src/libraries/System.Runtime.Serialization.Primitives/src/System.Runtime.Serialization.Primitives.csproj b/src/libraries/System.Runtime.Serialization.Primitives/src/System.Runtime.Serialization.Primitives.csproj
index e314354aef4a4..7026150754ea9 100644
--- a/src/libraries/System.Runtime.Serialization.Primitives/src/System.Runtime.Serialization.Primitives.csproj
+++ b/src/libraries/System.Runtime.Serialization.Primitives/src/System.Runtime.Serialization.Primitives.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <Nullable>enable</Nullable>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System\Runtime\Serialization\CollectionDataContractAttribute.cs" />
diff --git a/src/libraries/System.Runtime.Serialization.Xml/ref/System.Runtime.Serialization.Xml.csproj b/src/libraries/System.Runtime.Serialization.Xml/ref/System.Runtime.Serialization.Xml.csproj
index 4e128a35ab0c3..a79c1b8fae254 100644
--- a/src/libraries/System.Runtime.Serialization.Xml/ref/System.Runtime.Serialization.Xml.csproj
+++ b/src/libraries/System.Runtime.Serialization.Xml/ref/System.Runtime.Serialization.Xml.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Runtime.Serialization.Xml/src/System.Runtime.Serialization.Xml.csproj b/src/libraries/System.Runtime.Serialization.Xml/src/System.Runtime.Serialization.Xml.csproj
index dfb110cefca46..7834886d24914 100644
--- a/src/libraries/System.Runtime.Serialization.Xml/src/System.Runtime.Serialization.Xml.csproj
+++ b/src/libraries/System.Runtime.Serialization.Xml/src/System.Runtime.Serialization.Xml.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Runtime/ref/System.Runtime.csproj b/src/libraries/System.Runtime/ref/System.Runtime.csproj
index 9cbad9dddb804..1bdbbe8c5bffc 100644
--- a/src/libraries/System.Runtime/ref/System.Runtime.csproj
+++ b/src/libraries/System.Runtime/ref/System.Runtime.csproj
@@ -8,7 +8,7 @@
         Remove warning disable when nullable attributes are respected,
         Type has no accessible constructors which use only CLS-compliant types -->
     <NoWarn>$(NoWarn);0809;0618;CS8614;CS3015</NoWarn>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <PropertyGroup>
diff --git a/src/libraries/System.Runtime/src/System.Runtime.csproj b/src/libraries/System.Runtime/src/System.Runtime.csproj
index 8d726a1314792..b8df760b6ba3f 100644
--- a/src/libraries/System.Runtime/src/System.Runtime.csproj
+++ b/src/libraries/System.Runtime/src/System.Runtime.csproj
@@ -3,7 +3,7 @@
     <!-- Pull type forwards from the experimental ref assembly so we only need to maintain a single src project -->
     <ContractProject>$(LibrariesProjectRoot)System.Runtime.Experimental\ref\System.Runtime.Experimental.csproj</ContractProject>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
     <!-- The following 2 lines disable the automatic generation of the [RequiresPreviewFeatures] assembly level attribute and set LangVersion to Preview on the latest TFM-->
     <EnablePreviewFeatures>True</EnablePreviewFeatures>
diff --git a/src/libraries/System.Runtime/tests/System.Runtime.Tests.csproj b/src/libraries/System.Runtime/tests/System.Runtime.Tests.csproj
index 051fe609d634b..c45a71ac87238 100644
--- a/src/libraries/System.Runtime/tests/System.Runtime.Tests.csproj
+++ b/src/libraries/System.Runtime/tests/System.Runtime.Tests.csproj
@@ -247,7 +247,7 @@
     <Compile Include="System\Type\TypeTests.Get.cs" />
     <Compile Include="$(CommonTestPath)System\RandomDataGenerator.cs" Link="Common\System\RandomDataGenerator.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="System\ExitCodeTests.Unix.cs" />
   </ItemGroup>
   <ItemGroup Condition="'$(FeatureGenericMath)' == 'true'">
diff --git a/src/libraries/System.Security.AccessControl/ref/System.Security.AccessControl.csproj b/src/libraries/System.Security.AccessControl/ref/System.Security.AccessControl.csproj
index 391997c918a93..46e8ce511e772 100644
--- a/src/libraries/System.Security.AccessControl/ref/System.Security.AccessControl.csproj
+++ b/src/libraries/System.Security.AccessControl/ref/System.Security.AccessControl.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Security.AccessControl/src/System.Security.AccessControl.csproj b/src/libraries/System.Security.AccessControl/src/System.Security.AccessControl.csproj
index 98ab4777d2f60..8bdc585baa15c 100644
--- a/src/libraries/System.Security.AccessControl/src/System.Security.AccessControl.csproj
+++ b/src/libraries/System.Security.AccessControl/src/System.Security.AccessControl.csproj
@@ -6,9 +6,10 @@
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsWindows)' != 'true'">SR.PlatformNotSupported_AccessControl</GeneratePlatformNotSupportedAssemblyMessage>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' != 'windows'">SR.PlatformNotSupported_AccessControl</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\Security\AccessControl\ACE.cs" />
     <Compile Include="System\Security\AccessControl\ACL.cs" />
     <Compile Include="System\Security\AccessControl\CommonObjectSecurity.cs" />
diff --git a/src/libraries/System.Security.Claims/ref/System.Security.Claims.csproj b/src/libraries/System.Security.Claims/ref/System.Security.Claims.csproj
index 33820c6233231..df5828adf2014 100644
--- a/src/libraries/System.Security.Claims/ref/System.Security.Claims.csproj
+++ b/src/libraries/System.Security.Claims/ref/System.Security.Claims.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Security.Claims/src/System.Security.Claims.csproj b/src/libraries/System.Security.Claims/src/System.Security.Claims.csproj
index ca4bd80a6eb1c..3af8bb328c7d3 100644
--- a/src/libraries/System.Security.Claims/src/System.Security.Claims.csproj
+++ b/src/libraries/System.Security.Claims/src/System.Security.Claims.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Security.Cryptography.Algorithms/ref/System.Security.Cryptography.Algorithms.csproj b/src/libraries/System.Security.Cryptography.Algorithms/ref/System.Security.Cryptography.Algorithms.csproj
index 6f78fdf5bfd12..959864f04e657 100644
--- a/src/libraries/System.Security.Cryptography.Algorithms/ref/System.Security.Cryptography.Algorithms.csproj
+++ b/src/libraries/System.Security.Cryptography.Algorithms/ref/System.Security.Cryptography.Algorithms.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <NoWarn>$(NoWarn);SYSLIB0021;SYSLIB0022</NoWarn>
     <Nullable>enable</Nullable>
   </PropertyGroup>
diff --git a/src/libraries/System.Security.Cryptography.Algorithms/src/System.Security.Cryptography.Algorithms.csproj b/src/libraries/System.Security.Cryptography.Algorithms/src/System.Security.Cryptography.Algorithms.csproj
index ccd9e34fe31e1..6af3caadf5a58 100644
--- a/src/libraries/System.Security.Cryptography.Algorithms/src/System.Security.Cryptography.Algorithms.csproj
+++ b/src/libraries/System.Security.Cryptography.Algorithms/src/System.Security.Cryptography.Algorithms.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Security.Cryptography.Cng/ref/System.Security.Cryptography.Cng.csproj b/src/libraries/System.Security.Cryptography.Cng/ref/System.Security.Cryptography.Cng.csproj
index a333acc015182..f9381da6532db 100644
--- a/src/libraries/System.Security.Cryptography.Cng/ref/System.Security.Cryptography.Cng.csproj
+++ b/src/libraries/System.Security.Cryptography.Cng/ref/System.Security.Cryptography.Cng.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Security.Cryptography.Cng/src/System.Security.Cryptography.Cng.csproj b/src/libraries/System.Security.Cryptography.Cng/src/System.Security.Cryptography.Cng.csproj
index 1fe031a388f59..40d5a22195c9f 100644
--- a/src/libraries/System.Security.Cryptography.Cng/src/System.Security.Cryptography.Cng.csproj
+++ b/src/libraries/System.Security.Cryptography.Cng/src/System.Security.Cryptography.Cng.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Security.Cryptography.Cng/tests/System.Security.Cryptography.Cng.Tests.csproj b/src/libraries/System.Security.Cryptography.Cng/tests/System.Security.Cryptography.Cng.Tests.csproj
index 3ab50a56b049e..e6d642f010d23 100644
--- a/src/libraries/System.Security.Cryptography.Cng/tests/System.Security.Cryptography.Cng.Tests.csproj
+++ b/src/libraries/System.Security.Cryptography.Cng/tests/System.Security.Cryptography.Cng.Tests.csproj
@@ -14,7 +14,7 @@
     <Compile Include="SymmetricCngTestHelpers.cs" />
     <Compile Include="TestData.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonTestPath)System\Security\Cryptography\AlgorithmImplementations\AES\AesCipherTests.Data.cs"
              Link="CommonTest\AlgorithmImplementations\AES\AesCipherTests.Data.cs" />
     <Compile Include="$(CommonTestPath)System\Security\Cryptography\AlgorithmImplementations\AES\AesCornerTests.cs"
@@ -140,8 +140,8 @@
              Link="CommonTest\System\Security\Cryptography\AlgorithmImplementations\RSA\RSAXml.cs" />
     <Compile Include="$(CommonTestPath)System\Security\Cryptography\AlgorithmImplementations\RSA\SignVerify.netcoreapp.cs"
              Link="CommonTest\System\Security\Cryptography\AlgorithmImplementations\RSA\SignVerify.netcoreapp.cs" />
-    <Compile Condition="'$(TargetsWindows)' == 'true'" Include="AesCngTests.cs" />
-    <Compile Condition="'$(TargetsWindows)' == 'true'" Include="TripleDESCngTests.cs" />
+    <Compile Condition="'$(TargetPlatformIdentifier)' == 'windows'" Include="AesCngTests.cs" />
+    <Compile Condition="'$(TargetPlatformIdentifier)' == 'windows'" Include="TripleDESCngTests.cs" />
     <Compile Include="$(CommonTestPath)System\Security\Cryptography\AlgorithmImplementations\TripleDES\TripleDESContractTests.cs"
              Link="CommonTest\System\Security\Cryptography\AlgorithmImplementations\TripleDES\TripleDESContractTests.cs" />
     <Compile Include="$(CommonTestPath)System\Security\Cryptography\AlgorithmImplementations\AES\AesContractTests.cs"
@@ -152,11 +152,11 @@
              Link="CommonTest\System\Security\Cryptography\AlgorithmImplementations\TripleDES\TripleDESCipherOneShotTests.cs" />
     <Compile Include="$(CommonTestPath)System\Security\Cryptography\AlgorithmImplementations\AES\AesModeTests.cs"
              Link="CommonTest\AlgorithmImplementations\AES\AesModeTests.cs" />
-    <Compile Condition="'$(TargetsWindows)' == 'true'" Include="$(CommonTestPath)System\Security\Cryptography\AlgorithmImplementations\TripleDES\TripleDESReusabilityTests.cs"
+    <Compile Condition="'$(TargetPlatformIdentifier)' == 'windows'" Include="$(CommonTestPath)System\Security\Cryptography\AlgorithmImplementations\TripleDES\TripleDESReusabilityTests.cs"
              Link="CommonTest\System\Security\Cryptography\AlgorithmImplementations\TripleDES\TripleDESReusabilityTests.cs" />
-    <Compile Condition="'$(TargetsWindows)' == 'true'" Include="$(CommonTestPath)System\Security\Cryptography\AlgorithmImplementations\AES\AesCipherTests.cs"
+    <Compile Condition="'$(TargetPlatformIdentifier)' == 'windows'" Include="$(CommonTestPath)System\Security\Cryptography\AlgorithmImplementations\AES\AesCipherTests.cs"
              Link="CommonTest\AlgorithmImplementations\AES\AesCipherTests.cs" />
-    <Compile Condition="'$(TargetsWindows)' == 'true'" Include="$(CommonTestPath)System\Security\Cryptography\AlgorithmImplementations\AES\AesCipherOneShotTests.cs"
+    <Compile Condition="'$(TargetPlatformIdentifier)' == 'windows'" Include="$(CommonTestPath)System\Security\Cryptography\AlgorithmImplementations\AES\AesCipherOneShotTests.cs"
              Link="CommonTest\AlgorithmImplementations\AES\AesCipherTests.OneShot" />
     <Compile Include="ECDiffieHellmanCngTests.cs" />
     <Compile Include="$(CommonTestPath)System\Security\Cryptography\AlgorithmImplementations\ECDiffieHellman\ECDiffieHellmanTests.cs"
diff --git a/src/libraries/System.Security.Cryptography.Csp/ref/System.Security.Cryptography.Csp.csproj b/src/libraries/System.Security.Cryptography.Csp/ref/System.Security.Cryptography.Csp.csproj
index 19181bd717eef..ceccd4c842655 100644
--- a/src/libraries/System.Security.Cryptography.Csp/ref/System.Security.Cryptography.Csp.csproj
+++ b/src/libraries/System.Security.Cryptography.Csp/ref/System.Security.Cryptography.Csp.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <NoWarn>$(NoWarn);CS0809</NoWarn>
     <Nullable>enable</Nullable>
   </PropertyGroup>
diff --git a/src/libraries/System.Security.Cryptography.Csp/src/System.Security.Cryptography.Csp.csproj b/src/libraries/System.Security.Cryptography.Csp/src/System.Security.Cryptography.Csp.csproj
index 722700b99b151..5e5200e76e470 100644
--- a/src/libraries/System.Security.Cryptography.Csp/src/System.Security.Cryptography.Csp.csproj
+++ b/src/libraries/System.Security.Cryptography.Csp/src/System.Security.Cryptography.Csp.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="System.Memory" />
diff --git a/src/libraries/System.Security.Cryptography.Encoding/ref/System.Security.Cryptography.Encoding.csproj b/src/libraries/System.Security.Cryptography.Encoding/ref/System.Security.Cryptography.Encoding.csproj
index 482a8c25218fd..e11be11a50cfe 100644
--- a/src/libraries/System.Security.Cryptography.Encoding/ref/System.Security.Cryptography.Encoding.csproj
+++ b/src/libraries/System.Security.Cryptography.Encoding/ref/System.Security.Cryptography.Encoding.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Security.Cryptography.Encoding/src/System.Security.Cryptography.Encoding.csproj b/src/libraries/System.Security.Cryptography.Encoding/src/System.Security.Cryptography.Encoding.csproj
index da0251ebe3492..6102b48ffc294 100644
--- a/src/libraries/System.Security.Cryptography.Encoding/src/System.Security.Cryptography.Encoding.csproj
+++ b/src/libraries/System.Security.Cryptography.Encoding/src/System.Security.Cryptography.Encoding.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
     <Nullable>enable</Nullable>
   </PropertyGroup>
diff --git a/src/libraries/System.Security.Cryptography.OpenSsl/ref/System.Security.Cryptography.OpenSsl.csproj b/src/libraries/System.Security.Cryptography.OpenSsl/ref/System.Security.Cryptography.OpenSsl.csproj
index 225e8cf688082..474b4123f3b60 100644
--- a/src/libraries/System.Security.Cryptography.OpenSsl/ref/System.Security.Cryptography.OpenSsl.csproj
+++ b/src/libraries/System.Security.Cryptography.OpenSsl/ref/System.Security.Cryptography.OpenSsl.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Security.Cryptography.OpenSsl/src/System.Security.Cryptography.OpenSsl.csproj b/src/libraries/System.Security.Cryptography.OpenSsl/src/System.Security.Cryptography.OpenSsl.csproj
index 1fe031a388f59..40d5a22195c9f 100644
--- a/src/libraries/System.Security.Cryptography.OpenSsl/src/System.Security.Cryptography.OpenSsl.csproj
+++ b/src/libraries/System.Security.Cryptography.OpenSsl/src/System.Security.Cryptography.OpenSsl.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Security.Cryptography.OpenSsl/tests/System.Security.Cryptography.OpenSsl.Tests.csproj b/src/libraries/System.Security.Cryptography.OpenSsl/tests/System.Security.Cryptography.OpenSsl.Tests.csproj
index e139314a91c37..c57a5864c559c 100644
--- a/src/libraries/System.Security.Cryptography.OpenSsl/tests/System.Security.Cryptography.OpenSsl.Tests.csproj
+++ b/src/libraries/System.Security.Cryptography.OpenSsl/tests/System.Security.Cryptography.OpenSsl.Tests.csproj
@@ -5,7 +5,7 @@
         https://github.com/dotnet/runtime/issues/49083 -->
     <IgnoreForCI Condition="'$(TargetOS)' == 'OSX' and '$(TargetArchitecture)' == 'arm64' ">true</IgnoreForCI>
     <!-- The library is not supported on mobile platforms (PNSE) -->
-    <IgnoreForCI Condition="'$(TargetsAndroid)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true'">true</IgnoreForCI>
+    <IgnoreForCI Condition="'$(TargetOS)' == 'Android' or '$(TargetOS)' == 'iOS' or '$(TargetOS)' == 'tvOS'">true</IgnoreForCI>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <EnableDllImportGenerator>true</EnableDllImportGenerator>
   </PropertyGroup>
diff --git a/src/libraries/System.Security.Cryptography.Pkcs/src/System.Security.Cryptography.Pkcs.csproj b/src/libraries/System.Security.Cryptography.Pkcs/src/System.Security.Cryptography.Pkcs.csproj
index 4c0f530d5faed..57ed54ee88f0a 100644
--- a/src/libraries/System.Security.Cryptography.Pkcs/src/System.Security.Cryptography.Pkcs.csproj
+++ b/src/libraries/System.Security.Cryptography.Pkcs/src/System.Security.Cryptography.Pkcs.csproj
@@ -16,12 +16,12 @@ System.Security.Cryptography.Pkcs.EnvelopedCms</PackageDescription>
     <IsPartialFacadeAssembly Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETFramework'">true</IsPartialFacadeAssembly>
     <OmitResources Condition="'$(IsPartialFacadeAssembly)' == 'true'">true</OmitResources>
   </PropertyGroup>
+
   <Import Project="$(CommonPath)System\Security\Cryptography\Asn1\AsnXml.targets" Condition="'$(IsPartialFacadeAssembly)' != 'true'" />
   <Import Project="$(CommonPath)System\Security\Cryptography\Asn1Reader\System.Security.Cryptography.Asn1Reader.Shared.projitems" Condition="'$(IsPartialFacadeAssembly)' != 'true'" />
-  <!-- Don't delete these clauses even if they look useless. They tell the VS IDE that "Windows_Debug", etc., are
-       valid configuration for this project and stop it from trying to "fix up" the .sln file -->
-  <!-- API types (platform independent) -->
+
   <ItemGroup Condition="'$(IsPartialFacadeAssembly)' != 'true'">
+    <!-- API types (platform independent) -->
     <Compile Include="System\Security\Cryptography\CryptographicAttributeObject.cs" />
     <Compile Include="System\Security\Cryptography\CryptographicAttributeObjectCollection.cs" />
     <Compile Include="System\Security\Cryptography\CryptographicAttributeObjectEnumerator.cs" />
@@ -49,11 +49,8 @@ System.Security.Cryptography.Pkcs.EnvelopedCms</PackageDescription>
     <Compile Include="System\Security\Cryptography\Pkcs\SubjectIdentifierOrKeyType.cs" />
     <Compile Include="System\Security\Cryptography\Pkcs\SubjectIdentifierType.cs" />
     <Compile Include="System\Security\Cryptography\Xml\X509IssuerSerial.cs" />
-  </ItemGroup>
-  <ItemGroup Condition="'$(IsPartialFacadeAssembly)' == 'true'">
-  </ItemGroup>
-  <!-- Internal types (platform independent) -->
-  <ItemGroup Condition="'$(IsPartialFacadeAssembly)' != 'true'">
+
+     <!-- Internal types (platform independent) -->
     <Compile Include="Internal\Cryptography\DecryptorPal.cs" />
     <Compile Include="Internal\Cryptography\KeyAgreeRecipientInfoPal.cs" />
     <Compile Include="Internal\Cryptography\KeyLengths.cs" />
@@ -65,13 +62,6 @@ System.Security.Cryptography.Pkcs.EnvelopedCms</PackageDescription>
              Link="Internal\Cryptography\Helpers.cs" />
     <Compile Include="$(CommonPath)System\HexConverter.cs"
              Link="Common\System\HexConverter.cs" />
-  </ItemGroup>
-  <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0'))">
-    <Compile Include="$(CommonPath)DisableRuntimeMarshalling.cs"
-             Link="Common\DisableRuntimeMarshalling.cs" />
-  </ItemGroup>
-  <!-- Internal types (platform: AnyOS) -->
-  <ItemGroup Condition="'$(IsPartialFacadeAssembly)' != 'true'">
     <AsnXml Include="$(CommonPath)System\Security\Cryptography\Asn1\Pkcs7\ContentInfoAsn.xml">
       <Link>Common\System\Security\Cryptography\Asn1\Pkcs7\ContentInfoAsn.xml</Link>
     </AsnXml>
@@ -144,8 +134,14 @@ System.Security.Cryptography.Pkcs.EnvelopedCms</PackageDescription>
       <DependentUpon>System\Security\Cryptography\Pkcs\Asn1\RecipientKeyIdentifier.xml</DependentUpon>
     </Compile>
   </ItemGroup>
-  <!-- Internal types (platform: Windows) -->
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true' and '$(IsPartialFacadeAssembly)' != 'true'">
+
+  <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0'))">
+    <Compile Include="$(CommonPath)DisableRuntimeMarshalling.cs"
+             Link="Common\DisableRuntimeMarshalling.cs" />
+  </ItemGroup>
+
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
+    <!-- Internal types (platform: Windows) -->
     <Compile Include="Internal\Cryptography\Pal\Windows\AlgId.cs" />
     <Compile Include="Internal\Cryptography\Pal\Windows\DecryptorPalWindows.cs" />
     <Compile Include="Internal\Cryptography\Pal\Windows\DecryptorPalWindows.Decode.cs" />
@@ -163,9 +159,8 @@ System.Security.Cryptography.Pkcs.EnvelopedCms</PackageDescription>
     <Compile Include="Microsoft\Win32\SafeHandles\SafeHeapAllocHandle.cs" />
     <Compile Include="Microsoft\Win32\SafeHandles\SafeProvOrNCryptKeyHandle.cs" />
     <Compile Include="Microsoft\Win32\SafeHandles\SafeProvOrNCryptKeyHandleUwp.cs" />
-  </ItemGroup>
-  <!-- Interop types (platform: Windows) -->
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true' and '$(IsPartialFacadeAssembly)' != 'true'">
+
+    <!-- Interop types (platform: Windows) -->
     <Compile Include="$(CommonPath)Interop\Windows\Advapi32\Interop.CryptAcquireContext.cs"
              Link="Common\Interop\Windows\Advapi32\Interop.CryptAcquireContext.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Advapi32\Interop.CryptDestroyHash.cs"
@@ -308,18 +303,19 @@ System.Security.Cryptography.Pkcs.EnvelopedCms</PackageDescription>
              Link="Common\Interop\Windows\NCrypt\Interop.NCryptFreeObject.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
              Link="Common\Interop\Windows\Interop.Libraries.cs" />
-  </ItemGroup>
-  <!-- Common types (platform: Windows) -->
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true' and '$(IsPartialFacadeAssembly)' != 'true'">
+
+    <!-- Common types (platform: Windows) -->
     <Compile Include="$(CommonPath)Internal\Cryptography\Windows\CryptoThrowHelper.cs"
              Link="Common\Internal\Cryptography\Windows\CryptoThrowHelper.cs" />
     <Compile Include="$(CommonPath)Microsoft\Win32\SafeHandles\SafeHandleCache.cs"
              Link="Common\Microsoft\Win32\SafeHandles\SafeHandleCache.cs" />
   </ItemGroup>
+
   <!-- Internal types (platform: AnyOS) -->
-  <ItemGroup Condition="'$(TargetsWindows)' != 'true' and '$(IsPartialFacadeAssembly)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'windows' and '$(IsPartialFacadeAssembly)' != 'true'">
     <Compile Include="Internal\Cryptography\Pal\AnyOS\PkcsPal.AnyOS.cs" />
   </ItemGroup>
+
   <ItemGroup Condition="'$(IsPartialFacadeAssembly)' != 'true'">
     <Compile Include="$(CommonPath)System\Obsoletions.cs"
              Link="Common\System\Obsoletions.cs" />
@@ -563,6 +559,7 @@ System.Security.Cryptography.Pkcs.EnvelopedCms</PackageDescription>
     <Compile Include="System\Security\Cryptography\Pkcs\SignerInfoCollection.cs" />
     <Compile Include="System\Security\Cryptography\Pkcs\SignerInfoEnumerator.cs" />
   </ItemGroup>
+
   <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'netstandard2.1'))">
     <Compile Include="$(CommonPath)System\Security\Cryptography\KeyFormatHelper.cs"
              Link="Common\System\Security\Cryptography\KeyFormatHelper.cs" />
@@ -675,7 +672,7 @@ System.Security.Cryptography.Pkcs.EnvelopedCms</PackageDescription>
   <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0'))">
     <Reference Include="System.Security.Cryptography" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp' and '$(IsPartialFacadeAssembly)' != 'true'">
+  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETStandard'">
     <PackageReference Include="System.Security.Cryptography.Cng" Version="$(SystemSecurityCryptographyCngVersion)" />
   </ItemGroup>
   <ItemGroup Condition="$(TargetFramework.StartsWith('netstandard2.0'))">
diff --git a/src/libraries/System.Security.Cryptography.Pkcs/tests/System.Security.Cryptography.Pkcs.Tests.csproj b/src/libraries/System.Security.Cryptography.Pkcs/tests/System.Security.Cryptography.Pkcs.Tests.csproj
index b2c2be9f8f022..dbcbe329391ba 100644
--- a/src/libraries/System.Security.Cryptography.Pkcs/tests/System.Security.Cryptography.Pkcs.Tests.csproj
+++ b/src/libraries/System.Security.Cryptography.Pkcs/tests/System.Security.Cryptography.Pkcs.Tests.csproj
@@ -39,7 +39,7 @@
     <Compile Include="EnvelopedCms\DecryptTestsRsaPaddingModeTests.cs" />
     <Compile Include="EnvelopedCms\DecryptTestsUsingExplicitPrivateKey.cs" />
     <Compile Include="EnvelopedCms\KeyTransRecipientInfoRsaOaepCertTests.cs" />
-    <Compile Include="EnvelopedCms\DecryptTests.KeyPersistence.cs" Condition="'$(TargetsWindows)' == 'true'" />
+    <Compile Include="EnvelopedCms\DecryptTests.KeyPersistence.cs" Condition="'$(TargetPlatformIdentifier)' == 'windows'" />
     <Compile Include="EnvelopedCms\KeyTransRecipientInfoRsaPaddingModeTests.cs" />
     <Compile Include="EnvelopedCms\SubjectIdentifierTests.cs" />
     <Compile Include="Pkcs12\CertBagTests.cs" />
diff --git a/src/libraries/System.Security.Cryptography.Primitives/ref/System.Security.Cryptography.Primitives.csproj b/src/libraries/System.Security.Cryptography.Primitives/ref/System.Security.Cryptography.Primitives.csproj
index 85b76a7c36907..958cfe9a0761a 100644
--- a/src/libraries/System.Security.Cryptography.Primitives/ref/System.Security.Cryptography.Primitives.csproj
+++ b/src/libraries/System.Security.Cryptography.Primitives/ref/System.Security.Cryptography.Primitives.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Security.Cryptography.Primitives/src/System.Security.Cryptography.Primitives.csproj b/src/libraries/System.Security.Cryptography.Primitives/src/System.Security.Cryptography.Primitives.csproj
index 01600a4d505ca..d3eb8cf67d361 100644
--- a/src/libraries/System.Security.Cryptography.Primitives/src/System.Security.Cryptography.Primitives.csproj
+++ b/src/libraries/System.Security.Cryptography.Primitives/src/System.Security.Cryptography.Primitives.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Security.Cryptography.ProtectedData/src/System.Security.Cryptography.ProtectedData.csproj b/src/libraries/System.Security.Cryptography.ProtectedData/src/System.Security.Cryptography.ProtectedData.csproj
index 4880ca0aa094d..9d505846d2f94 100644
--- a/src/libraries/System.Security.Cryptography.ProtectedData/src/System.Security.Cryptography.ProtectedData.csproj
+++ b/src/libraries/System.Security.Cryptography.ProtectedData/src/System.Security.Cryptography.ProtectedData.csproj
@@ -13,11 +13,12 @@ System.Security.Cryptography.ProtectedData</PackageDescription>
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
     <IsPartialFacadeAssembly Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETFramework'">true</IsPartialFacadeAssembly>
     <OmitResources Condition="'$(IsPartialFacadeAssembly)' == 'true'">true</OmitResources>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetsWindows)' != 'true'">SR.PlatformNotSupported_CryptographyProtectedData</GeneratePlatformNotSupportedAssemblyMessage>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetPlatformIdentifier)' != 'windows'">SR.PlatformNotSupported_CryptographyProtectedData</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="System\Security\Cryptography\DataProtectionScope.cs" />
     <Compile Include="System\Security\Cryptography\ProtectedData.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Crypt32\Interop.CryptProtectData.cs"
@@ -39,7 +40,7 @@ System.Security.Cryptography.ProtectedData</PackageDescription>
     <Compile Include="$(CommonPath)System\HResults.cs"
              Link="Common\System\HResults.cs" />
   </ItemGroup>
-  <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0')) and '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0-windows'))">
     <Compile Include="$(CommonPath)DisableRuntimeMarshalling.cs"
              Link="Common\DisableRuntimeMarshalling.cs" />
   </ItemGroup>
diff --git a/src/libraries/System.Security.Cryptography.X509Certificates/ref/System.Security.Cryptography.X509Certificates.csproj b/src/libraries/System.Security.Cryptography.X509Certificates/ref/System.Security.Cryptography.X509Certificates.csproj
index 71d56f25038d4..c195646e0e51c 100644
--- a/src/libraries/System.Security.Cryptography.X509Certificates/ref/System.Security.Cryptography.X509Certificates.csproj
+++ b/src/libraries/System.Security.Cryptography.X509Certificates/ref/System.Security.Cryptography.X509Certificates.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
     <NoWarn>$(NoWarn);SYSLIB0026</NoWarn>
   </PropertyGroup>
diff --git a/src/libraries/System.Security.Cryptography.X509Certificates/src/System.Security.Cryptography.X509Certificates.csproj b/src/libraries/System.Security.Cryptography.X509Certificates/src/System.Security.Cryptography.X509Certificates.csproj
index 1fe031a388f59..40d5a22195c9f 100644
--- a/src/libraries/System.Security.Cryptography.X509Certificates/src/System.Security.Cryptography.X509Certificates.csproj
+++ b/src/libraries/System.Security.Cryptography.X509Certificates/src/System.Security.Cryptography.X509Certificates.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Security.Cryptography.X509Certificates/tests/System.Security.Cryptography.X509Certificates.Tests.csproj b/src/libraries/System.Security.Cryptography.X509Certificates/tests/System.Security.Cryptography.X509Certificates.Tests.csproj
index 2155c7384eff5..fe4112c15fe4a 100644
--- a/src/libraries/System.Security.Cryptography.X509Certificates/tests/System.Security.Cryptography.X509Certificates.Tests.csproj
+++ b/src/libraries/System.Security.Cryptography.X509Certificates/tests/System.Security.Cryptography.X509Certificates.Tests.csproj
@@ -2,15 +2,17 @@
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <DefineConstants>$(DefineConstants);HAVE_THUMBPRINT_OVERLOADS</DefineConstants>
-    <DefineConstants Condition="'$(TargetsUnix)' == 'true'">$(DefineConstants);Unix</DefineConstants>
     <IncludeRemoteExecutor>true</IncludeRemoteExecutor>
     <NoWarn>$(NoWarn);SYSLIB0026;SYSLIB0027;SYSLIB0028</NoWarn>
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent)-Android;$(NetCoreAppCurrent)-Browser;$(NetCoreAppCurrent)-OSX;$(NetCoreAppCurrent)-iOS;$(NetCoreAppCurrent)-tvOS</TargetFrameworks>
     <EnableDllImportGenerator>true</EnableDllImportGenerator>
   </PropertyGroup>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <UseAndroidCrypto Condition="'$(TargetsAndroid)' == 'true'">true</UseAndroidCrypto>
-    <UseAppleCrypto Condition="'$(TargetsOSX)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true'">true</UseAppleCrypto>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Android' or '$(TargetPlatformIdentifier)' == 'OSX' or '$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'tvOS'">$(DefineConstants);Unix</DefineConstants>
+    <UseAndroidCrypto Condition="'$(TargetPlatformIdentifier)' == 'Android'">true</UseAndroidCrypto>
+    <UseAppleCrypto Condition="'$(TargetPlatformIdentifier)' == 'OSX' or '$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'tvOS'">true</UseAppleCrypto>
   </PropertyGroup>
   <Import Project="$(CommonPath)System\Security\Cryptography\Asn1Reader\System.Security.Cryptography.Asn1Reader.Shared.projitems" />
   <ItemGroup>
@@ -79,7 +81,7 @@
     <Compile Include="$(CommonPath)DisableRuntimeMarshalling.cs"
              Link="Common\DisableRuntimeMarshalling.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' and '$(UseAndroidCrypto)' != 'true' and '$(UseAppleCrypto)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'windows' and '$(TargetPlatformIdentifier)' != 'Browser' and '$(UseAndroidCrypto)' != 'true' and '$(UseAppleCrypto)' != 'true'">
     <Compile Include="X509FilesystemTests.Unix.cs" />
     <Compile Include="X509StoreTests.Unix.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.ChMod.cs"
@@ -126,7 +128,7 @@
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs"
              Link="Common\Interop\Unix\Interop.Libraries.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(UseAppleCrypto)' == 'true' AND '$(TargetsOSX)' == 'true'">
+  <ItemGroup Condition="'$(UseAppleCrypto)' == 'true' and '$(TargetPlatformIdentifier)' == 'OSX'">
     <Compile Include="X509StoreMutableTests.OSX.cs" />
     <Compile Include="$(CommonPath)Interop\OSX\Interop.CoreFoundation.cs"
              Link="Common\Interop\OSX\Interop.CoreFoundation.cs" />
@@ -155,7 +157,7 @@
     <Compile Include="$(CommonPath)Microsoft\Win32\SafeHandles\SafeHandleCache.cs"
              Link="Common\Microsoft\Win32\SafeHandles\SafeHandleCache.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(UseAppleCrypto)' == 'true' AND '$(TargetsOSX)' != 'true'">
+  <ItemGroup Condition="'$(UseAppleCrypto)' == 'true' and '$(TargetPlatformIdentifier)' != 'OSX'">
     <Compile Include="X509StoreMutableTests.iOS.cs" />
   </ItemGroup>
   <ItemGroup>
@@ -163,7 +165,7 @@
     <ProjectReference Include="$(LibrariesProjectRoot)System.Security.Cryptography.Pkcs\src\System.Security.Cryptography.Pkcs.csproj" />
     <PackageReference Include="System.Security.Cryptography.X509Certificates.TestData" Version="$(SystemSecurityCryptographyX509CertificatesTestDataVersion)" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)Interop\Windows\Crypt32\Interop.CERT_CONTEXT.cs"
              Link="Common\Interop\Windows\Crypt32\Interop.CERT_CONTEXT.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Crypt32\Interop.CERT_INFO.cs"
diff --git a/src/libraries/System.Security.Cryptography/ref/System.Security.Cryptography.csproj b/src/libraries/System.Security.Cryptography/ref/System.Security.Cryptography.csproj
index 0b9ddef821dad..27dbb3a844b32 100644
--- a/src/libraries/System.Security.Cryptography/ref/System.Security.Cryptography.csproj
+++ b/src/libraries/System.Security.Cryptography/ref/System.Security.Cryptography.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
     <NoWarn>$(NoWarn);SYSLIB0026</NoWarn>
   </PropertyGroup>
diff --git a/src/libraries/System.Security.Cryptography/src/System.Security.Cryptography.csproj b/src/libraries/System.Security.Cryptography/src/System.Security.Cryptography.csproj
index b503389947d91..e76f61affe9de 100644
--- a/src/libraries/System.Security.Cryptography/src/System.Security.Cryptography.csproj
+++ b/src/libraries/System.Security.Cryptography/src/System.Security.Cryptography.csproj
@@ -3,22 +3,24 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <DefineConstants>$(DefineConstants);INTERNAL_ASYMMETRIC_IMPLEMENTATIONS</DefineConstants>
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent)-Android;$(NetCoreAppCurrent)-OSX;$(NetCoreAppCurrent)-iOS;$(NetCoreAppCurrent)-tvOS;$(NetCoreAppCurrent)-Browser;$(NetCoreAppCurrent)</TargetFrameworks>
-    <NoWarn>$(NoWarn);CA5350;CA5351;CA5379;CA5384</NoWarn>
+    <NoWarn>$(NoWarn);CA5350;CA5351;CA5379;CA5384;SYSLIB0026</NoWarn>
     <Nullable>enable</Nullable>
   </PropertyGroup>
+
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsAnyOS)' == 'true'">SR.SystemSecurityCryptography_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
-    <NoWarn>$(NoWarn);SYSLIB0026</NoWarn>
-  </PropertyGroup>
-  <PropertyGroup>
-    <UseAndroidCrypto Condition="'$(TargetsAndroid)' == 'true'">true</UseAndroidCrypto>
-    <UseAppleCrypto Condition="'$(TargetsOSX)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true'">true</UseAppleCrypto>
-    <UseOpenSsl Condition="'$(TargetsUnix)' == 'true' and '$(UseAndroidCrypto)' != 'true' and '$(UseAppleCrypto)' != 'true'">true</UseOpenSsl>
-    <UseOpenSslAead Condition="'$(UseOpenSsl)' == 'true' or '$(TargetsOSX)' == 'true'">true</UseOpenSslAead>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == ''">SR.SystemSecurityCryptography_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
+    <UseAndroidCrypto Condition="'$(TargetPlatformIdentifier)' == 'Android'">true</UseAndroidCrypto>
+    <UseAppleCrypto Condition="'$(TargetPlatformIdentifier)' == 'OSX' or '$(TargetPlatformIdentifier)' == 'iOS' or '$(TargetPlatformIdentifier)' == 'tvOS'">true</UseAppleCrypto>
+    <UseOpenSsl Condition="'$(TargetPlatformIdentifier)' == 'Unix'">true</UseOpenSsl>
+    <UseOpenSslAead Condition="'$(UseOpenSsl)' == 'true' or '$(TargetPlatformIdentifier)' == 'OSX'">true</UseOpenSslAead>
     <NeedOpenSslInitializer Condition="'$(UseOpenSslAead)' == 'true'">true</NeedOpenSslInitializer>
   </PropertyGroup>
+
   <Import Project="$(CommonPath)System\Security\Cryptography\Asn1\AsnXml.targets" Condition="'$(GeneratePlatformNotSupportedAssemblyMessage)' == ''" />
   <Import Project="$(CommonPath)System\Security\Cryptography\Asn1Reader\System.Security.Cryptography.Asn1Reader.Shared.projitems" Condition="'$(GeneratePlatformNotSupportedAssemblyMessage)' == ''" />
+
   <ItemGroup Condition="'$(GeneratePlatformNotSupportedAssemblyMessage)' == ''">
     <Compile Include="$(CommonPath)DisableRuntimeMarshalling.cs"
              Link="Common\DisableRuntimeMarshalling.cs" />
@@ -533,7 +535,7 @@
       <DependentUpon>System\Security\Cryptography\X509Certificates\Asn1\PolicyInformationAsn.xml</DependentUpon>
     </Compile>
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsBrowser)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Browser'">
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs"
              Link="Common\Interop\Unix\Interop.Libraries.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.GetRandomBytes.cs"
@@ -1207,7 +1209,7 @@
     <Compile Include="System\Security\Cryptography\X509Certificates\X509Pal.Apple.ECKey.cs" />
     <Compile Include="System\Security\Cryptography\X509Certificates\X509Pal.Apple.X500Name.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsOSX)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'OSX'">
     <Compile Include="$(CommonPath)Microsoft\Win32\SafeHandles\Asn1SafeHandles.Unix.cs"
              Link="Common\Microsoft\Win32\SafeHandles\Asn1SafeHandles.Unix.cs" />
     <Compile Include="$(CommonPath)Microsoft\Win32\SafeHandles\SafeBignumHandle.Unix.cs"
@@ -1299,7 +1301,7 @@
     <Compile Include="System\Security\Cryptography\X509Certificates\StorePal.macOS.LoaderPal.cs" />
     <Compile Include="System\Security\Cryptography\X509Certificates\X509Pal.macOS.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(UseAppleCrypto)' == 'true' AND '$(TargetsOSX)' != 'true'">
+  <ItemGroup Condition="'$(UseAppleCrypto)' == 'true' and '$(TargetPlatformIdentifier)' != 'OSX'">
     <Compile Include="$(CommonPath)Interop\OSX\System.Security.Cryptography.Native.Apple\Interop.Keychain.iOS.cs"
              Link="Common\Interop\OSX\System.Security.Cryptography.Native.Apple\Interop.Keychain.iOS.cs" />
     <Compile Include="$(CommonPath)Interop\OSX\System.Security.Cryptography.Native.Apple\Interop.X509.iOS.cs"
@@ -1328,7 +1330,7 @@
     <Compile Include="System\Security\Cryptography\X509Certificates\UnsupportedDisallowedStore.cs" />
     <Compile Include="System\Security\Cryptography\X509Certificates\X509Pal.iOS.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)Internal\Cryptography\BasicSymmetricCipherBCrypt.cs"
              Link="Common\Internal\Cryptography\BasicSymmetricCipherBCrypt.cs" />
     <Compile Include="$(CommonPath)Internal\Cryptography\BasicSymmetricCipherLiteBCrypt.cs"
@@ -1827,7 +1829,7 @@
     <Reference Include="System.Threading" />
     <Reference Include="System.Threading.Thread" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != '' and '$(TargetPlatformIdentifier)' != 'windows' and '$(TargetPlatformIdentifier' != 'Browser'">
     <Reference Include="System.Console" Condition="'$(Configuration)' == 'Debug'" />
   </ItemGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Security.Cryptography/tests/System.Security.Cryptography.Tests.csproj b/src/libraries/System.Security.Cryptography/tests/System.Security.Cryptography.Tests.csproj
index dafa4adb4bff2..0f028bf8d148f 100644
--- a/src/libraries/System.Security.Cryptography/tests/System.Security.Cryptography.Tests.csproj
+++ b/src/libraries/System.Security.Cryptography/tests/System.Security.Cryptography.Tests.csproj
@@ -6,8 +6,10 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <EnableDllImportGenerator>true</EnableDllImportGenerator>
   </PropertyGroup>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <UseAndroidCrypto Condition="'$(TargetsAndroid)' == 'true'">true</UseAndroidCrypto>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <UseAndroidCrypto Condition="'$(TargetPlatformIdentifier)' == 'Android'">true</UseAndroidCrypto>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="$(CommonTestPath)System\IO\ConnectedStreams.cs"
@@ -274,11 +276,11 @@
     <Compile Include="TripleDesTests.cs" />
     <Compile Include="ZeroMemoryTests.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="DefaultECDsaProvider.Windows.cs" />
     <Compile Include="DefaultECDiffieHellmanProvider.Windows.cs" />
   </ItemGroup>
-  <ItemGroup Condition="('$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true') and '$(UseAndroidCrypto)' != 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'windows' and '$(UseAndroidCrypto)' != 'true'">
     <Compile Include="DefaultECDsaProvider.Unix.cs" />
     <Compile Include="DefaultECDiffieHellmanProvider.Unix.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs"
diff --git a/src/libraries/System.Security.Permissions/tests/System.Security.Permissions.Tests.csproj b/src/libraries/System.Security.Permissions/tests/System.Security.Permissions.Tests.csproj
index b95e5766e1b9f..ad4d8340d6751 100644
--- a/src/libraries/System.Security.Permissions/tests/System.Security.Permissions.Tests.csproj
+++ b/src/libraries/System.Security.Permissions/tests/System.Security.Permissions.Tests.csproj
@@ -20,7 +20,7 @@
     <Compile Include="SecurityElementTests.cs" />
     <Compile Include="TrustManagerContextTests.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup>
     <Compile Include="XamlLoadPermissionTests.cs"/>
   </ItemGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Security.Principal.Windows/ref/System.Security.Principal.Windows.csproj b/src/libraries/System.Security.Principal.Windows/ref/System.Security.Principal.Windows.csproj
index 955e29d0da1ff..51a48de7604ce 100644
--- a/src/libraries/System.Security.Principal.Windows/ref/System.Security.Principal.Windows.csproj
+++ b/src/libraries/System.Security.Principal.Windows/ref/System.Security.Principal.Windows.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Security.Principal.Windows/src/System.Security.Principal.Windows.csproj b/src/libraries/System.Security.Principal.Windows/src/System.Security.Principal.Windows.csproj
index f99bbc6888141..e1b2637e0864a 100644
--- a/src/libraries/System.Security.Principal.Windows/src/System.Security.Principal.Windows.csproj
+++ b/src/libraries/System.Security.Principal.Windows/src/System.Security.Principal.Windows.csproj
@@ -1,19 +1,20 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)</TargetFrameworks>
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
-  <PropertyGroup Condition="'$(TargetsWindows)' != 'true'">
-    <GeneratePlatformNotSupportedAssemblyMessage>SR.PlatformNotSupported_Principal</GeneratePlatformNotSupportedAssemblyMessage>
+  <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' != 'windows'">SR.PlatformNotSupported_Principal</GeneratePlatformNotSupportedAssemblyMessage>
     <!-- Work around 'notsupported.cs' source generation of explicit interface implementations issue -->
     <!-- https://github.com/dotnet/arcade/issues/4722 -->
-    <Nullable>annotations</Nullable>
+    <Nullable Condition="'$(GeneratePlatformNotSupportedAssemblyMessage)' != ''">annotations</Nullable>
   </PropertyGroup>
 
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="Microsoft\Win32\SafeHandles\SafeAccessTokenHandle.cs" />
     <Compile Include="System\Security\Principal\IdentityNotMappedException.cs" />
     <Compile Include="System\Security\Principal\IdentityReference.cs" />
diff --git a/src/libraries/System.Security.Principal/ref/System.Security.Principal.csproj b/src/libraries/System.Security.Principal/ref/System.Security.Principal.csproj
index 06941c80cb779..94f0959b03801 100644
--- a/src/libraries/System.Security.Principal/ref/System.Security.Principal.csproj
+++ b/src/libraries/System.Security.Principal/ref/System.Security.Principal.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Security.Principal/src/System.Security.Principal.csproj b/src/libraries/System.Security.Principal/src/System.Security.Principal.csproj
index 4f2d15aa3b6a5..a9c43608342de 100644
--- a/src/libraries/System.Security.Principal/src/System.Security.Principal.csproj
+++ b/src/libraries/System.Security.Principal/src/System.Security.Principal.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Security.SecureString/ref/System.Security.SecureString.csproj b/src/libraries/System.Security.SecureString/ref/System.Security.SecureString.csproj
index 38d76bbb6123d..69f78b5ef868d 100644
--- a/src/libraries/System.Security.SecureString/ref/System.Security.SecureString.csproj
+++ b/src/libraries/System.Security.SecureString/ref/System.Security.SecureString.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Security.SecureString/src/System.Security.SecureString.csproj b/src/libraries/System.Security.SecureString/src/System.Security.SecureString.csproj
index c1ef027e6f6aa..817af0da46521 100644
--- a/src/libraries/System.Security.SecureString/src/System.Security.SecureString.csproj
+++ b/src/libraries/System.Security.SecureString/src/System.Security.SecureString.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.ServiceProcess.ServiceController/src/System.ServiceProcess.ServiceController.csproj b/src/libraries/System.ServiceProcess.ServiceController/src/System.ServiceProcess.ServiceController.csproj
index 4ee87fe36d329..44fc5893c98de 100644
--- a/src/libraries/System.ServiceProcess.ServiceController/src/System.ServiceProcess.ServiceController.csproj
+++ b/src/libraries/System.ServiceProcess.ServiceController/src/System.ServiceProcess.ServiceController.csproj
@@ -14,13 +14,14 @@ System.ServiceProcess.ServiceType</PackageDescription>
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
     <IsPartialFacadeAssembly Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETFramework'">true</IsPartialFacadeAssembly>
     <OmitResources Condition="'$(IsPartialFacadeAssembly)' == 'true'">true</OmitResources>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetsWindows)' != 'true'">SR.PlatformNotSupported_ServiceController</GeneratePlatformNotSupportedAssemblyMessage>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetPlatformIdentifier)' != 'windows'">SR.PlatformNotSupported_ServiceController</GeneratePlatformNotSupportedAssemblyMessage>
     <!-- we cannot add API on .NETStandard since it would be absent on .NETFramework, suppress warnings that require API changes -->
     <NoWarn Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETStandard'">$(NoWarn);CA1066</NoWarn>
   </PropertyGroup>
-  <ItemGroup Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)System\Text\ValueStringBuilder.cs"
              Link="Common\System\Text\ValueStringBuilder.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
diff --git a/src/libraries/System.Speech/src/System.Speech.csproj b/src/libraries/System.Speech/src/System.Speech.csproj
index 7003b449eff78..8e92c747dd754 100644
--- a/src/libraries/System.Speech/src/System.Speech.csproj
+++ b/src/libraries/System.Speech/src/System.Speech.csproj
@@ -17,12 +17,14 @@ Commonly Used Types
 System.Speech.Synthesis.SpeechSynthesizer
 System.Speech.Recognition.SpeechRecognizer</PackageDescription>
   </PropertyGroup>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
     <!-- System.Speech has its own SR scheme in which resource ID's are mapped to SAPI error codes. So we disable our default SR.cs generation and include resources explicitly -->
-    <OmitResources Condition="'$(TargetsWindows)' == 'true'">true</OmitResources>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsWindows)' != 'true'">SR.PlatformNotSupported_SystemSpeech</GeneratePlatformNotSupportedAssemblyMessage>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' != 'windows'">SR.PlatformNotSupported_SystemSpeech</GeneratePlatformNotSupportedAssemblyMessage>
+    <OmitResources Condition="'$(GeneratePlatformNotSupportedAssemblyMessage)' == ''">true</OmitResources>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="SR.cs" />
     <Compile Include="SRID.cs" />
     <Compile Include="AudioFormat\AudioFormatConverter.cs" />
@@ -221,11 +223,11 @@ System.Speech.Recognition.SpeechRecognizer</PackageDescription>
     <Compile Include="$(CommonPath)Interop\Windows\WinMm\Interop.waveOutWrite.cs"
             Link="Common\Interop\Windows\WinMm\Interop.waveOutWrite.cs" />
   </ItemGroup>
-  <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0')) and '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0-windows'))">
     <Compile Include="$(CommonPath)DisableRuntimeMarshalling.cs"
              Link="Common\DisableRuntimeMarshalling.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <EmbeddedResource Include="Resources\Strings.resx">
       <Visible>true</Visible>
       <ManifestResourceName>ExceptionStringTable</ManifestResourceName>
diff --git a/src/libraries/System.Text.Encoding.CodePages/src/System.Text.Encoding.CodePages.csproj b/src/libraries/System.Text.Encoding.CodePages/src/System.Text.Encoding.CodePages.csproj
index 094f9c43ec7db..2dc3052b7602f 100644
--- a/src/libraries/System.Text.Encoding.CodePages/src/System.Text.Encoding.CodePages.csproj
+++ b/src/libraries/System.Text.Encoding.CodePages/src/System.Text.Encoding.CodePages.csproj
@@ -44,7 +44,7 @@ System.Text.CodePagesEncodingProvider</PackageDescription>
     <Compile Include="System\Text\ISCIIEncoding.cs" />
     <Compile Include="System\Text\SBCSCodePageEncoding.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true' or '$(TargetFrameworkIdentifier)' == '.NETFramework'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows' or '$(TargetFrameworkIdentifier)' == '.NETFramework'">
     <Compile Include="System\Text\CodePagesEncodingProvider.Windows.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
              Link="Common\Interop\Windows\Interop.Libraries.cs" />
@@ -57,7 +57,7 @@ System.Text.CodePagesEncodingProvider</PackageDescription>
     <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.WideCharToMultiByte.cs"
              Link="Common\Interop\Windows\Kernel32\Interop.WideCharToMultiByte.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' != '.NETFramework' and '$(TargetsWindows)' != 'true'">
+  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' != '.NETFramework' and '$(TargetPlatformIdentifier)' != 'windows'">
     <Compile Include="System\Text\CodePagesEncodingProvider.Default.cs" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp'">
diff --git a/src/libraries/System.Text.Encoding.Extensions/ref/System.Text.Encoding.Extensions.csproj b/src/libraries/System.Text.Encoding.Extensions/ref/System.Text.Encoding.Extensions.csproj
index fa92b90a39b6c..0dcefeb2a1288 100644
--- a/src/libraries/System.Text.Encoding.Extensions/ref/System.Text.Encoding.Extensions.csproj
+++ b/src/libraries/System.Text.Encoding.Extensions/ref/System.Text.Encoding.Extensions.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Text.Encoding.Extensions/src/System.Text.Encoding.Extensions.csproj b/src/libraries/System.Text.Encoding.Extensions/src/System.Text.Encoding.Extensions.csproj
index dd3dc2940a54b..5ecfe239de6f7 100644
--- a/src/libraries/System.Text.Encoding.Extensions/src/System.Text.Encoding.Extensions.csproj
+++ b/src/libraries/System.Text.Encoding.Extensions/src/System.Text.Encoding.Extensions.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Text.Encoding/ref/System.Text.Encoding.csproj b/src/libraries/System.Text.Encoding/ref/System.Text.Encoding.csproj
index 7cfd7365e0d1a..01856a50e8420 100644
--- a/src/libraries/System.Text.Encoding/ref/System.Text.Encoding.csproj
+++ b/src/libraries/System.Text.Encoding/ref/System.Text.Encoding.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Text.Encoding/src/System.Text.Encoding.csproj b/src/libraries/System.Text.Encoding/src/System.Text.Encoding.csproj
index 4f2d15aa3b6a5..a9c43608342de 100644
--- a/src/libraries/System.Text.Encoding/src/System.Text.Encoding.csproj
+++ b/src/libraries/System.Text.Encoding/src/System.Text.Encoding.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Text.Encodings.Web/src/System.Text.Encodings.Web.csproj b/src/libraries/System.Text.Encodings.Web/src/System.Text.Encodings.Web.csproj
index ec39570c09d82..75702453c1fb5 100644
--- a/src/libraries/System.Text.Encodings.Web/src/System.Text.Encodings.Web.csproj
+++ b/src/libraries/System.Text.Encodings.Web/src/System.Text.Encodings.Web.csproj
@@ -16,7 +16,8 @@ System.Text.Encodings.Web.JavaScriptEncoder</PackageDescription>
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
-    <DefineConstants Condition="'$(TargetsBrowser)' == 'true'">$(DefineConstants);TARGET_BROWSER</DefineConstants>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'Browser'">$(DefineConstants);TARGET_BROWSER</DefineConstants>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System\IO\TextWriterExtensions.cs" />
diff --git a/src/libraries/System.Text.Encodings.Web/tools/GenDefinedCharList/GenDefinedCharList.csproj b/src/libraries/System.Text.Encodings.Web/tools/GenDefinedCharList/GenDefinedCharList.csproj
index da2080cc5e87a..d1b3c292347b2 100644
--- a/src/libraries/System.Text.Encodings.Web/tools/GenDefinedCharList/GenDefinedCharList.csproj
+++ b/src/libraries/System.Text.Encodings.Web/tools/GenDefinedCharList/GenDefinedCharList.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFrameworks>netcoreapp3.1</TargetFrameworks>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
     <EnableDefaultCompileItems>false</EnableDefaultCompileItems>
   </PropertyGroup>
   <PropertyGroup>
diff --git a/src/libraries/System.Text.Encodings.Web/tools/GenUnicodeRanges/GenUnicodeRanges.csproj b/src/libraries/System.Text.Encodings.Web/tools/GenUnicodeRanges/GenUnicodeRanges.csproj
index da2080cc5e87a..d1b3c292347b2 100644
--- a/src/libraries/System.Text.Encodings.Web/tools/GenUnicodeRanges/GenUnicodeRanges.csproj
+++ b/src/libraries/System.Text.Encodings.Web/tools/GenUnicodeRanges/GenUnicodeRanges.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFrameworks>netcoreapp3.1</TargetFrameworks>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
     <EnableDefaultCompileItems>false</EnableDefaultCompileItems>
   </PropertyGroup>
   <PropertyGroup>
diff --git a/src/libraries/System.Text.Json/gen/System.Text.Json.SourceGeneration.targets b/src/libraries/System.Text.Json/gen/System.Text.Json.SourceGeneration.targets
index 97d7815239648..f9e1d021b674b 100644
--- a/src/libraries/System.Text.Json/gen/System.Text.Json.SourceGeneration.targets
+++ b/src/libraries/System.Text.Json/gen/System.Text.Json.SourceGeneration.targets
@@ -1,6 +1,6 @@
 <Project>
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0</TargetFrameworks>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <AssemblyName>$(MSBuildThisFileName)</AssemblyName>
     <RootNamespace>$(MSBuildThisFileName)</RootNamespace>
     <StringResourcesClassName>SR</StringResourcesClassName>
diff --git a/src/libraries/System.Text.RegularExpressions/gen/System.Text.RegularExpressions.Generator.csproj b/src/libraries/System.Text.RegularExpressions/gen/System.Text.RegularExpressions.Generator.csproj
index e6982a3b83ce0..51c49cc2e6d48 100644
--- a/src/libraries/System.Text.RegularExpressions/gen/System.Text.RegularExpressions.Generator.csproj
+++ b/src/libraries/System.Text.RegularExpressions/gen/System.Text.RegularExpressions.Generator.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0</TargetFrameworks>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <EnableDefaultItems>true</EnableDefaultItems>
     <EnableDefaultEmbeddedResourceItems>false</EnableDefaultEmbeddedResourceItems>
     <UsingToolXliff>true</UsingToolXliff>
diff --git a/src/libraries/System.Text.RegularExpressions/ref/System.Text.RegularExpressions.csproj b/src/libraries/System.Text.RegularExpressions/ref/System.Text.RegularExpressions.csproj
index 9b41914783020..1a11a90ac115e 100644
--- a/src/libraries/System.Text.RegularExpressions/ref/System.Text.RegularExpressions.csproj
+++ b/src/libraries/System.Text.RegularExpressions/ref/System.Text.RegularExpressions.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Text.RegularExpressions/src/System.Text.RegularExpressions.csproj b/src/libraries/System.Text.RegularExpressions/src/System.Text.RegularExpressions.csproj
index 0034d373563a9..641d32f355310 100644
--- a/src/libraries/System.Text.RegularExpressions/src/System.Text.RegularExpressions.csproj
+++ b/src/libraries/System.Text.RegularExpressions/src/System.Text.RegularExpressions.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Threading.AccessControl/src/System.Threading.AccessControl.csproj b/src/libraries/System.Threading.AccessControl/src/System.Threading.AccessControl.csproj
index 572fbfcb4e6cd..7c73b994648a0 100644
--- a/src/libraries/System.Threading.AccessControl/src/System.Threading.AccessControl.csproj
+++ b/src/libraries/System.Threading.AccessControl/src/System.Threading.AccessControl.csproj
@@ -18,10 +18,11 @@ System.Security.AccessControl.SemaphoreSecurity</PackageDescription>
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
     <IsPartialFacadeAssembly Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETFramework'">true</IsPartialFacadeAssembly>
-    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetsWindows)' != 'true'">SR.PlatformNotSupported_AccessControl</GeneratePlatformNotSupportedAssemblyMessage>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetPlatformIdentifier)' != 'windows'">SR.PlatformNotSupported_AccessControl</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
-  <ItemGroup Condition="'$(IsPartialFacadeAssembly)' != 'true' and '$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Errors.cs"
              Link="Common\Interop\Windows\Interop.Errors.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.BOOL.cs"
diff --git a/src/libraries/System.Threading.Overlapped/ref/System.Threading.Overlapped.csproj b/src/libraries/System.Threading.Overlapped/ref/System.Threading.Overlapped.csproj
index f015797103dbd..689e572b0d1f0 100644
--- a/src/libraries/System.Threading.Overlapped/ref/System.Threading.Overlapped.csproj
+++ b/src/libraries/System.Threading.Overlapped/ref/System.Threading.Overlapped.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Threading.Overlapped/src/System.Threading.Overlapped.csproj b/src/libraries/System.Threading.Overlapped/src/System.Threading.Overlapped.csproj
index dd3dc2940a54b..5ecfe239de6f7 100644
--- a/src/libraries/System.Threading.Overlapped/src/System.Threading.Overlapped.csproj
+++ b/src/libraries/System.Threading.Overlapped/src/System.Threading.Overlapped.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Threading.Tasks.Extensions/ref/System.Threading.Tasks.Extensions.csproj b/src/libraries/System.Threading.Tasks.Extensions/ref/System.Threading.Tasks.Extensions.csproj
index 76e0ee495e8fd..2a359768071e2 100644
--- a/src/libraries/System.Threading.Tasks.Extensions/ref/System.Threading.Tasks.Extensions.csproj
+++ b/src/libraries/System.Threading.Tasks.Extensions/ref/System.Threading.Tasks.Extensions.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Threading.Tasks.Extensions/src/System.Threading.Tasks.Extensions.csproj b/src/libraries/System.Threading.Tasks.Extensions/src/System.Threading.Tasks.Extensions.csproj
index 4f2d15aa3b6a5..a9c43608342de 100644
--- a/src/libraries/System.Threading.Tasks.Extensions/src/System.Threading.Tasks.Extensions.csproj
+++ b/src/libraries/System.Threading.Tasks.Extensions/src/System.Threading.Tasks.Extensions.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Threading.Tasks.Parallel/ref/System.Threading.Tasks.Parallel.csproj b/src/libraries/System.Threading.Tasks.Parallel/ref/System.Threading.Tasks.Parallel.csproj
index aa3558ef5bd59..300626789bb46 100644
--- a/src/libraries/System.Threading.Tasks.Parallel/ref/System.Threading.Tasks.Parallel.csproj
+++ b/src/libraries/System.Threading.Tasks.Parallel/ref/System.Threading.Tasks.Parallel.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Threading.Tasks.Parallel/src/System.Threading.Tasks.Parallel.csproj b/src/libraries/System.Threading.Tasks.Parallel/src/System.Threading.Tasks.Parallel.csproj
index fc06ab309921c..16c2fc66318e7 100644
--- a/src/libraries/System.Threading.Tasks.Parallel/src/System.Threading.Tasks.Parallel.csproj
+++ b/src/libraries/System.Threading.Tasks.Parallel/src/System.Threading.Tasks.Parallel.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Threading.Tasks/ref/System.Threading.Tasks.csproj b/src/libraries/System.Threading.Tasks/ref/System.Threading.Tasks.csproj
index fd998b62bb803..abb8e0de95b27 100644
--- a/src/libraries/System.Threading.Tasks/ref/System.Threading.Tasks.csproj
+++ b/src/libraries/System.Threading.Tasks/ref/System.Threading.Tasks.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Threading.Tasks/src/System.Threading.Tasks.csproj b/src/libraries/System.Threading.Tasks/src/System.Threading.Tasks.csproj
index 4f2d15aa3b6a5..a9c43608342de 100644
--- a/src/libraries/System.Threading.Tasks/src/System.Threading.Tasks.csproj
+++ b/src/libraries/System.Threading.Tasks/src/System.Threading.Tasks.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Threading.Thread/ref/System.Threading.Thread.csproj b/src/libraries/System.Threading.Thread/ref/System.Threading.Thread.csproj
index 2ebad89669d3d..8fd273891553d 100644
--- a/src/libraries/System.Threading.Thread/ref/System.Threading.Thread.csproj
+++ b/src/libraries/System.Threading.Thread/ref/System.Threading.Thread.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Threading.Thread/src/System.Threading.Thread.csproj b/src/libraries/System.Threading.Thread/src/System.Threading.Thread.csproj
index dd3dc2940a54b..5ecfe239de6f7 100644
--- a/src/libraries/System.Threading.Thread/src/System.Threading.Thread.csproj
+++ b/src/libraries/System.Threading.Thread/src/System.Threading.Thread.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Threading.ThreadPool/ref/System.Threading.ThreadPool.csproj b/src/libraries/System.Threading.ThreadPool/ref/System.Threading.ThreadPool.csproj
index a86046bb60d44..6d53cf798f598 100644
--- a/src/libraries/System.Threading.ThreadPool/ref/System.Threading.ThreadPool.csproj
+++ b/src/libraries/System.Threading.ThreadPool/ref/System.Threading.ThreadPool.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Threading.ThreadPool/src/System.Threading.ThreadPool.csproj b/src/libraries/System.Threading.ThreadPool/src/System.Threading.ThreadPool.csproj
index dd3dc2940a54b..5ecfe239de6f7 100644
--- a/src/libraries/System.Threading.ThreadPool/src/System.Threading.ThreadPool.csproj
+++ b/src/libraries/System.Threading.ThreadPool/src/System.Threading.ThreadPool.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Threading.Timer/ref/System.Threading.Timer.csproj b/src/libraries/System.Threading.Timer/ref/System.Threading.Timer.csproj
index 398e3eafe32ac..4ce7799f86ae1 100644
--- a/src/libraries/System.Threading.Timer/ref/System.Threading.Timer.csproj
+++ b/src/libraries/System.Threading.Timer/ref/System.Threading.Timer.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Threading.Timer/src/System.Threading.Timer.csproj b/src/libraries/System.Threading.Timer/src/System.Threading.Timer.csproj
index 4f2d15aa3b6a5..a9c43608342de 100644
--- a/src/libraries/System.Threading.Timer/src/System.Threading.Timer.csproj
+++ b/src/libraries/System.Threading.Timer/src/System.Threading.Timer.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Threading/ref/System.Threading.csproj b/src/libraries/System.Threading/ref/System.Threading.csproj
index 8a140934e7f27..a0726a8e926cd 100644
--- a/src/libraries/System.Threading/ref/System.Threading.csproj
+++ b/src/libraries/System.Threading/ref/System.Threading.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Threading/src/System.Threading.csproj b/src/libraries/System.Threading/src/System.Threading.csproj
index 895b458279376..f4f99d24965e2 100644
--- a/src/libraries/System.Threading/src/System.Threading.csproj
+++ b/src/libraries/System.Threading/src/System.Threading.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Transactions.Local/ref/System.Transactions.Local.csproj b/src/libraries/System.Transactions.Local/ref/System.Transactions.Local.csproj
index ce48f9db195f1..aa7f862958cc2 100644
--- a/src/libraries/System.Transactions.Local/ref/System.Transactions.Local.csproj
+++ b/src/libraries/System.Transactions.Local/ref/System.Transactions.Local.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Transactions.Local/src/System.Transactions.Local.csproj b/src/libraries/System.Transactions.Local/src/System.Transactions.Local.csproj
index 1715d21528c97..8180b39112f8c 100644
--- a/src/libraries/System.Transactions.Local/src/System.Transactions.Local.csproj
+++ b/src/libraries/System.Transactions.Local/src/System.Transactions.Local.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.ValueTuple/ref/System.ValueTuple.csproj b/src/libraries/System.ValueTuple/ref/System.ValueTuple.csproj
index 48439ada9ee5b..53c1df4d9a37f 100644
--- a/src/libraries/System.ValueTuple/ref/System.ValueTuple.csproj
+++ b/src/libraries/System.ValueTuple/ref/System.ValueTuple.csproj
@@ -3,7 +3,7 @@
     <!-- Must match version supported by frameworks which support 4.0.* inbox.
          Can be removed when API is added and this assembly is versioned to 4.1.* -->
     <AssemblyVersion>4.0.3.0</AssemblyVersion>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.ValueTuple/src/System.ValueTuple.csproj b/src/libraries/System.ValueTuple/src/System.ValueTuple.csproj
index 7a4c997055130..c3bdb22267397 100644
--- a/src/libraries/System.ValueTuple/src/System.ValueTuple.csproj
+++ b/src/libraries/System.ValueTuple/src/System.ValueTuple.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <!-- rev'ed to 4.0.1.0 even though 4.0.0.0 never shipped so that we can drop pre-release down to beta -->
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Web.HttpUtility/ref/System.Web.HttpUtility.csproj b/src/libraries/System.Web.HttpUtility/ref/System.Web.HttpUtility.csproj
index 0c8fb1555c678..3edccaeb578f5 100644
--- a/src/libraries/System.Web.HttpUtility/ref/System.Web.HttpUtility.csproj
+++ b/src/libraries/System.Web.HttpUtility/ref/System.Web.HttpUtility.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <Nullable>enable</Nullable>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System.Web.HttpUtility.cs" />
diff --git a/src/libraries/System.Web.HttpUtility/src/System.Web.HttpUtility.csproj b/src/libraries/System.Web.HttpUtility/src/System.Web.HttpUtility.csproj
index 2b5750a370783..31af47b3b1f78 100644
--- a/src/libraries/System.Web.HttpUtility/src/System.Web.HttpUtility.csproj
+++ b/src/libraries/System.Web.HttpUtility/src/System.Web.HttpUtility.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <Nullable>enable</Nullable>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System\Web\HttpUtility.cs" />
diff --git a/src/libraries/System.Windows.Extensions/src/System.Windows.Extensions.csproj b/src/libraries/System.Windows.Extensions/src/System.Windows.Extensions.csproj
index b2de19721e30a..3eebeafe4770e 100644
--- a/src/libraries/System.Windows.Extensions/src/System.Windows.Extensions.csproj
+++ b/src/libraries/System.Windows.Extensions/src/System.Windows.Extensions.csproj
@@ -12,10 +12,11 @@ System.Security.Cryptography.X509Certificates.X509Certificate2UI
 System.Security.Cryptography.X509Certificates.X509SelectionFlag</PackageDescription>
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
-  <PropertyGroup Condition="'$(TargetsWindows)' != 'true'">
-    <GeneratePlatformNotSupportedAssemblyMessage>SR.PlatformNotSupported_System_Windows_Extensions</GeneratePlatformNotSupportedAssemblyMessage>
+  <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' != 'windows'">SR.PlatformNotSupported_System_Windows_Extensions</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">
     <Compile Include="TypeForwards.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Crypt32\Interop.CERT_CONTEXT.cs"
              Link="Common\Interop\Windows\Crypt32\Interop.CERT_CONTEXT.cs" />
@@ -82,7 +83,7 @@ System.Security.Cryptography.X509Certificates.X509SelectionFlag</PackageDescript
     <Compile Include="System\Media\SystemSounds.cs" />
     <Compile Include="System\Xaml\Permissions\XamlAccessLevel.cs" />
   </ItemGroup>
-  <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0')) and '$(TargetsAnyOS)' != 'true'">
+  <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0')) and '$(TargetPlatformIdentifier)' != ''">
     <Compile Include="$(CommonPath)DisableRuntimeMarshalling.cs"
              Link="Common\DisableRuntimeMarshalling.cs" />
   </ItemGroup>
diff --git a/src/libraries/System.Windows.Extensions/tests/System.Windows.Extensions.Tests.csproj b/src/libraries/System.Windows.Extensions/tests/System.Windows.Extensions.Tests.csproj
index fac6e53faf410..310e822d4cf8b 100644
--- a/src/libraries/System.Windows.Extensions/tests/System.Windows.Extensions.Tests.csproj
+++ b/src/libraries/System.Windows.Extensions/tests/System.Windows.Extensions.Tests.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent)-windows</TargetFrameworks>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
+  <ItemGroup>
     <Compile Include="X509Certificate2UITests.cs" />
     <Compile Include="X509Certificate2UIManualTests.cs" />
     <Compile Include="XamlAccessLevelTests.cs" />
diff --git a/src/libraries/System.Xml.ReaderWriter/ref/System.Xml.ReaderWriter.csproj b/src/libraries/System.Xml.ReaderWriter/ref/System.Xml.ReaderWriter.csproj
index 7ce26ea71e1fd..025908422291e 100644
--- a/src/libraries/System.Xml.ReaderWriter/ref/System.Xml.ReaderWriter.csproj
+++ b/src/libraries/System.Xml.ReaderWriter/ref/System.Xml.ReaderWriter.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Xml.ReaderWriter/src/System.Xml.ReaderWriter.csproj b/src/libraries/System.Xml.ReaderWriter/src/System.Xml.ReaderWriter.csproj
index 87b021333ac17..43a3ccb9fcc01 100644
--- a/src/libraries/System.Xml.ReaderWriter/src/System.Xml.ReaderWriter.csproj
+++ b/src/libraries/System.Xml.ReaderWriter/src/System.Xml.ReaderWriter.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <RootNamespace>System.Xml</RootNamespace>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Xml.XDocument/ref/System.Xml.XDocument.csproj b/src/libraries/System.Xml.XDocument/ref/System.Xml.XDocument.csproj
index e49f7c30e2e34..4c769629707a8 100644
--- a/src/libraries/System.Xml.XDocument/ref/System.Xml.XDocument.csproj
+++ b/src/libraries/System.Xml.XDocument/ref/System.Xml.XDocument.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Xml.XDocument/src/System.Xml.XDocument.csproj b/src/libraries/System.Xml.XDocument/src/System.Xml.XDocument.csproj
index a27331293a226..81fe13f13dafd 100644
--- a/src/libraries/System.Xml.XDocument/src/System.Xml.XDocument.csproj
+++ b/src/libraries/System.Xml.XDocument/src/System.Xml.XDocument.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <RootNamespace>System.Xml</RootNamespace>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Xml.XPath.XDocument/ref/System.Xml.XPath.XDocument.csproj b/src/libraries/System.Xml.XPath.XDocument/ref/System.Xml.XPath.XDocument.csproj
index 1bc5c5bd1fe48..ada222c6f4056 100644
--- a/src/libraries/System.Xml.XPath.XDocument/ref/System.Xml.XPath.XDocument.csproj
+++ b/src/libraries/System.Xml.XPath.XDocument/ref/System.Xml.XPath.XDocument.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Xml.XPath.XDocument/src/System.Xml.XPath.XDocument.csproj b/src/libraries/System.Xml.XPath.XDocument/src/System.Xml.XPath.XDocument.csproj
index 456c96962cd9f..f910114697193 100644
--- a/src/libraries/System.Xml.XPath.XDocument/src/System.Xml.XPath.XDocument.csproj
+++ b/src/libraries/System.Xml.XPath.XDocument/src/System.Xml.XPath.XDocument.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Xml.XPath/ref/System.Xml.XPath.csproj b/src/libraries/System.Xml.XPath/ref/System.Xml.XPath.csproj
index 6cbf41c40f82b..01888d73a15db 100644
--- a/src/libraries/System.Xml.XPath/ref/System.Xml.XPath.csproj
+++ b/src/libraries/System.Xml.XPath/ref/System.Xml.XPath.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Xml.XPath/src/System.Xml.XPath.csproj b/src/libraries/System.Xml.XPath/src/System.Xml.XPath.csproj
index a2a87b23e74cf..d8e7c78820a1a 100644
--- a/src/libraries/System.Xml.XPath/src/System.Xml.XPath.csproj
+++ b/src/libraries/System.Xml.XPath/src/System.Xml.XPath.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Xml.XmlDocument/ref/System.Xml.XmlDocument.csproj b/src/libraries/System.Xml.XmlDocument/ref/System.Xml.XmlDocument.csproj
index 1844179cd812d..b6e90cfde9d43 100644
--- a/src/libraries/System.Xml.XmlDocument/ref/System.Xml.XmlDocument.csproj
+++ b/src/libraries/System.Xml.XmlDocument/ref/System.Xml.XmlDocument.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Xml.XmlDocument/src/System.Xml.XmlDocument.csproj b/src/libraries/System.Xml.XmlDocument/src/System.Xml.XmlDocument.csproj
index e6d999dc4c2ff..a46b8c977682a 100644
--- a/src/libraries/System.Xml.XmlDocument/src/System.Xml.XmlDocument.csproj
+++ b/src/libraries/System.Xml.XmlDocument/src/System.Xml.XmlDocument.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Xml.XmlSerializer/ref/System.Xml.XmlSerializer.csproj b/src/libraries/System.Xml.XmlSerializer/ref/System.Xml.XmlSerializer.csproj
index a626176aed788..901bd833ca5df 100644
--- a/src/libraries/System.Xml.XmlSerializer/ref/System.Xml.XmlSerializer.csproj
+++ b/src/libraries/System.Xml.XmlSerializer/ref/System.Xml.XmlSerializer.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/System.Xml.XmlSerializer/src/System.Xml.XmlSerializer.csproj b/src/libraries/System.Xml.XmlSerializer/src/System.Xml.XmlSerializer.csproj
index a2a87b23e74cf..d8e7c78820a1a 100644
--- a/src/libraries/System.Xml.XmlSerializer/src/System.Xml.XmlSerializer.csproj
+++ b/src/libraries/System.Xml.XmlSerializer/src/System.Xml.XmlSerializer.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/libraries/externals.csproj b/src/libraries/externals.csproj
index c04d47d9f897e..20eed5139a994 100644
--- a/src/libraries/externals.csproj
+++ b/src/libraries/externals.csproj
@@ -3,7 +3,7 @@
     <!-- Set the RuntimeIdentifier so that the DotNetHost and DotNetHostPolicy packages resolve for the corresponding runtime. -->
     <RuntimeIdentifier>$(PackageRID)</RuntimeIdentifier>
     <SwapNativeForIL Condition="'$(SwapNativeForIL)' == '' and ('$(Configuration)' == 'Debug' or '$(Coverage)' == 'true') and '$(RuntimeFlavor)' != 'Mono'">true</SwapNativeForIL>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <!-- Binplace properties -->
     <BinPlaceForTargetVertical>false</BinPlaceForTargetVertical>
     <BinPlaceNative>true</BinPlaceNative>
diff --git a/src/libraries/native-binplace.proj b/src/libraries/native-binplace.proj
index 9d9ee882b1f62..82427d8f27b01 100644
--- a/src/libraries/native-binplace.proj
+++ b/src/libraries/native-binplace.proj
@@ -2,7 +2,6 @@
   <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.props" />
 
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
     <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
     <BinPlaceRuntime>false</BinPlaceRuntime>
     <BinPlaceNative>true</BinPlaceNative>
diff --git a/src/libraries/pretest.proj b/src/libraries/pretest.proj
index dc879eb62d5f1..ac410f828662b 100644
--- a/src/libraries/pretest.proj
+++ b/src/libraries/pretest.proj
@@ -17,7 +17,7 @@
     the targeting and runtimepack before the test runners which consume that asset are built.
   -->
   <ItemGroup>
-    <ExternalsProject Include="externals.csproj" />
+    <ExternalsProject Include="externals.csproj" Condition="'$(BuildTargetFramework)' == '$(NetCoreAppCurrent)' or '$(BuildTargetFramework)' == ''" />
     <ProjectReference Include="@(ExternalsProject)" Condition="'$(MSBuildRestoreSessionId)' != ''" />
 
     <ProjectReference Include="$(CommonTestPath)AppleTestRunner\AppleTestRunner.csproj" Condition="'$(TargetOS)' == 'MacCatalyst' or '$(TargetOS)' == 'iOS' or '$(TargetOS)' == 'iOSSimulator' or '$(TargetOS)' == 'tvOS' or '$(TargetOS)' == 'tvOSSimulator'"/>
diff --git a/src/libraries/ref.proj b/src/libraries/ref.proj
index e3a63ad2bb848..4d67c2f01c6b9 100644
--- a/src/libraries/ref.proj
+++ b/src/libraries/ref.proj
@@ -6,6 +6,13 @@
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
+  <PropertyGroup Condition="'$(BuildTargetFramework)' == 'net48'">
+    <TargetFramework>$(BuildTargetFramework)</TargetFramework>
+    <!-- Filter out ProjectReferences which aren't compatible with the above TargetFramework. -->
+    <OmitIncompatibleProjectReferences>true</OmitIncompatibleProjectReferences>
+    <FilterTraversalProjectReferences>true</FilterTraversalProjectReferences>
+  </PropertyGroup>
+
   <ItemGroup>
     <_allRef Include="$(MSBuildThisFileDirectory)*\ref\*.csproj"
              Exclude="@(ProjectExclusions)" />
diff --git a/src/libraries/sendtohelix.proj b/src/libraries/sendtohelix.proj
index f5fd1292fed26..3b938a0168200 100644
--- a/src/libraries/sendtohelix.proj
+++ b/src/libraries/sendtohelix.proj
@@ -16,12 +16,11 @@
 
   <PropertyGroup>
     <BuildTargetFramework Condition="'$(BuildTargetFramework)' == ''">$(NetCoreAppCurrent)</BuildTargetFramework>
-    <TargetsWindows Condition="'$(TargetOS)' == 'windows'">true</TargetsWindows>
 
     <!-- Set the name of the scenario file. Note that this is only used in invocations where $(Scenario) is set
          (which is when this project is invoked to call the "CreateOneScenarioTestEnvFile" target). -->
-    <TestEnvFileName Condition=" '$(TargetsWindows)' == 'true' ">SetStressModes_$(Scenario).cmd</TestEnvFileName>
-    <TestEnvFileName Condition=" '$(TargetsWindows)' != 'true' ">SetStressModes_$(Scenario).sh</TestEnvFileName>
+    <TestEnvFileName Condition=" '$(TargetOS)' == 'windows' ">SetStressModes_$(Scenario).cmd</TestEnvFileName>
+    <TestEnvFileName Condition=" '$(TargetOS)' != 'windows' ">SetStressModes_$(Scenario).sh</TestEnvFileName>
 
   </PropertyGroup>
   
@@ -117,11 +116,12 @@
 
     <PropertyGroup>
       <TestEnvFilePath>$(NetCoreAppCurrentTestHostPath)$(TestEnvFileName)</TestEnvFilePath>
+      <_targetsWindows Condition="'$(TargetOS)' == 'windows'">true</_targetsWindows>
     </PropertyGroup>
 
     <ItemGroup>
       <_ProjectsToBuild Include="$(RepoRoot)\src\tests\Common\testenvironment.proj">
-        <Properties>Scenario=$(Scenario);TestEnvFileName=$(TestEnvFilePath);TargetsWindows=$(TargetsWindows)</Properties>
+        <Properties>Scenario=$(Scenario);TestEnvFileName=$(TestEnvFilePath);TargetsWindows=$(_targetsWindows)</Properties>
       </_ProjectsToBuild>
     </ItemGroup>
 
@@ -156,8 +156,8 @@
       <_RuntimeInput Include="$(NetCoreAppCurrentTestHostPath)**\*.dll" />
 
       <!-- Add the scenario TestEnv batch files -->
-      <_RuntimeInput Condition=" '$(Scenarios)' != '' and '$(TargetsWindows)' == 'true' " Include="$(NetCoreAppCurrentTestHostPath)**\*.cmd" />
-      <_RuntimeInput Condition=" '$(Scenarios)' != '' and '$(TargetsWindows)' != 'true' " Include="$(NetCoreAppCurrentTestHostPath)**\*.sh" />
+      <_RuntimeInput Condition="'$(Scenarios)' != '' and '$(TargetOS)' == 'windows'" Include="$(NetCoreAppCurrentTestHostPath)**\*.cmd" />
+      <_RuntimeInput Condition="'$(Scenarios)' != '' and '$(TargetOS)' != 'windows'" Include="$(NetCoreAppCurrentTestHostPath)**\*.sh" />
     </ItemGroup>
   </Target>
 
diff --git a/src/libraries/sendtohelixhelp.proj b/src/libraries/sendtohelixhelp.proj
index 3875c28fdf383..53a700a1eb2f9 100644
--- a/src/libraries/sendtohelixhelp.proj
+++ b/src/libraries/sendtohelixhelp.proj
@@ -6,8 +6,7 @@
   -->
 
   <PropertyGroup>
-    <TargetsWindows Condition="'$(TargetOS)' == 'windows'">true</TargetsWindows>
-    <WindowsShell Condition="'$(TargetsWindows)' == 'true' or '$(BrowserHost)' == 'windows'">true</WindowsShell>
+    <WindowsShell Condition="'$(TargetOS)' == 'windows' or '$(BrowserHost)' == 'windows'">true</WindowsShell>
 
     <!-- Set Helix build to build number if available -->
     <HelixBuild Condition="'$(HelixBuild)' == ''">$(BUILD_BUILDNUMBER)</HelixBuild>
@@ -98,15 +97,15 @@
          (which is when this project is invoked to call the "CreateTestEnvFile" target).
     -->
     <TestEnvFileName></TestEnvFileName>
-    <TestEnvFileName Condition=" '$(Scenario)' != '' and '$(TargetsWindows)' == 'true'">SetStressModes_$(Scenario).cmd</TestEnvFileName>
-    <TestEnvFileName Condition=" '$(Scenario)' != '' and '$(TargetsWindows)' != 'true' and '$(TargetOS)' != 'Browser'">SetStressModes_$(Scenario).sh</TestEnvFileName>
+    <TestEnvFileName Condition=" '$(Scenario)' != '' and '$(TargetOS)' == 'windows'">SetStressModes_$(Scenario).cmd</TestEnvFileName>
+    <TestEnvFileName Condition=" '$(Scenario)' != '' and '$(TargetOS)' != 'windows' and '$(TargetOS)' != 'Browser'">SetStressModes_$(Scenario).sh</TestEnvFileName>
   </PropertyGroup>
 
   <!-- HelixPreCommands is a set of commands run before the work item command. We use it here to inject
        setting up the per-scenario environment.
   -->
 
-  <ItemGroup Condition=" '$(TestEnvFileName)' != '' and '$(TargetsWindows)' == 'true' ">
+  <ItemGroup Condition=" '$(TestEnvFileName)' != '' and '$(TargetOS)' == 'windows' ">
     <HelixPreCommand Include="set __TestEnv=%HELIX_CORRELATION_PAYLOAD%\$(TestEnvFileName)" />
     <HelixPreCommand Include="type %__TestEnv%" />
     <HelixPreCommand Include="call %__TestEnv%" />
@@ -114,7 +113,7 @@
     <HelixPreCommand Include="set COMPlus" />
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TestEnvFileName)' != '' and '$(TargetsWindows)' != 'true' ">
+  <ItemGroup Condition=" '$(TestEnvFileName)' != '' and '$(TargetOS)' != 'windows' ">
     <HelixPreCommand Include="export __TestEnv=$HELIX_CORRELATION_PAYLOAD/$(TestEnvFileName)" />
     <HelixPreCommand Include="cat $__TestEnv" />
     <HelixPreCommand Include=". $__TestEnv" /> <!-- Use "." not "source"; some clients appear to run scripts with "sh" not "bash" -->
@@ -213,11 +212,11 @@
     <Message Importance="High" Text="Using Timeout: $(_workItemTimeout)" />
 
     <PropertyGroup Condition="'$(RuntimeFlavor)' == 'CoreCLR' and '$(BUILD_BUILDID)' != ''">
-      <HelixPostCommands Condition="'$(TargetsWindows)' == 'true'">
+      <HelixPostCommands Condition="'$(TargetOS)' == 'windows'">
         $(HelixPostCommands);
         %HELIX_PYTHONPATH% %HELIX_CORRELATION_PAYLOAD%\gen-debug-dump-docs.py -buildid $(BUILD_BUILDID) -workitem %HELIX_WORKITEM_FRIENDLYNAME% -jobid %HELIX_CORRELATION_ID% -outdir %HELIX_WORKITEM_UPLOAD_ROOT% -templatedir %HELIX_CORRELATION_PAYLOAD% -dumpdir %HELIX_DUMP_FOLDER% -productver $(ProductVersion)
       </HelixPostCommands>
-      <HelixPostCommands Condition="'$(TargetsWindows)' != 'true'">
+      <HelixPostCommands Condition="'$(TargetOS)' != 'windows'">
         $(HelixPostCommands);
         $HELIX_PYTHONPATH $HELIX_CORRELATION_PAYLOAD/gen-debug-dump-docs.py -buildid $(BUILD_BUILDID) -workitem $HELIX_WORKITEM_FRIENDLYNAME -jobid $HELIX_CORRELATION_ID -outdir $HELIX_WORKITEM_UPLOAD_ROOT -templatedir $HELIX_CORRELATION_PAYLOAD -dumpdir $HELIX_DUMP_FOLDER -productver $(ProductVersion)
       </HelixPostCommands>
diff --git a/src/libraries/shims/generated/Directory.Build.props b/src/libraries/shims/generated/Directory.Build.props
index 6b2ab04d6acff..4694448ae164b 100644
--- a/src/libraries/shims/generated/Directory.Build.props
+++ b/src/libraries/shims/generated/Directory.Build.props
@@ -11,7 +11,7 @@
   <Import Project="..\Directory.Build.props" />
 
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
 
   <!-- System.Data.SqlClient is not live built anymore, reference it manually. -->
diff --git a/src/libraries/shims/manual/Directory.Build.props b/src/libraries/shims/manual/Directory.Build.props
index e5f08175e8c44..d2bb299a05ed7 100644
--- a/src/libraries/shims/manual/Directory.Build.props
+++ b/src/libraries/shims/manual/Directory.Build.props
@@ -12,7 +12,7 @@
 
   <PropertyGroup>
     <IsRuntimeAssembly>true</IsRuntimeAssembly>
-    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/libraries/src.proj b/src/libraries/src.proj
index 4e0fea066f750..35479848aaee1 100644
--- a/src/libraries/src.proj
+++ b/src/libraries/src.proj
@@ -4,6 +4,13 @@
     <TraversalGlobalProperties>BuildAllProjects=true</TraversalGlobalProperties>
   </PropertyGroup>
 
+  <PropertyGroup Condition="'$(BuildTargetFramework)' == 'net48'">
+    <TargetFramework>$(BuildTargetFramework)</TargetFramework>
+    <!-- Filter out ProjectReferences which aren't compatible with the above TargetFramework. -->
+    <OmitIncompatibleProjectReferences>true</OmitIncompatibleProjectReferences>
+    <FilterTraversalProjectReferences>true</FilterTraversalProjectReferences>
+  </PropertyGroup>
+
   <ItemGroup>
     <_allSrc Include="$(MSBuildThisFileDirectory)*\src\*.*proj"
              Exclude="@(ProjectExclusions);
@@ -33,7 +40,7 @@
     <NetCoreAppProject Include="$(CoreLibProject);
                                 @(_allSrc)"
                        Exclude="@(NonNetCoreAppProject)" />
-    <ManualShimProject Include="shims\manual\*.csproj" />
+    <ManualShimProject Include="shims\manual\*.csproj" Condition="'$(BuildTargetFramework)' == '$(NetCoreAppCurrent)' or '$(BuildTargetFramework)' == ''" />
     <ApiCompatProject Include="shims\ApiCompat.proj"
                       Condition="'$(DotNetBuildFromSource)' != 'true' and
                                  ('$(BuildTargetFramework)' == '$(NetCoreAppCurrent)' or '$(BuildTargetFramework)' == '') and