diff --git a/packages/grpc-js-xds/src/lb-policy-registry.ts b/packages/grpc-js-xds/src/lb-policy-registry.ts
index 80a06323e..f7aa74254 100644
--- a/packages/grpc-js-xds/src/lb-policy-registry.ts
+++ b/packages/grpc-js-xds/src/lb-policy-registry.ts
@@ -15,6 +15,8 @@
  *
  */
 
+// https://github.com/grpc/proposal/blob/master/A52-xds-custom-lb-policies.md
+
 import { LoadBalancingConfig, experimental, logVerbosity } from "@grpc/grpc-js";
 import { LoadBalancingPolicy__Output } from "./generated/envoy/config/cluster/v3/LoadBalancingPolicy";
 import { TypedExtensionConfig__Output } from "./generated/envoy/config/core/v3/TypedExtensionConfig";
diff --git a/packages/grpc-js-xds/src/lb-policy-registry/round-robin.ts b/packages/grpc-js-xds/src/lb-policy-registry/round-robin.ts
index 311c8c38c..b43b1c9e3 100644
--- a/packages/grpc-js-xds/src/lb-policy-registry/round-robin.ts
+++ b/packages/grpc-js-xds/src/lb-policy-registry/round-robin.ts
@@ -15,6 +15,8 @@
  *
  */
 
+// https://github.com/grpc/proposal/blob/master/A52-xds-custom-lb-policies.md
+
 import { LoadBalancingConfig } from "@grpc/grpc-js";
 import { LoadBalancingPolicy__Output } from "../generated/envoy/config/cluster/v3/LoadBalancingPolicy";
 import { TypedExtensionConfig__Output } from "../generated/envoy/config/core/v3/TypedExtensionConfig";
diff --git a/packages/grpc-js-xds/src/lb-policy-registry/typed-struct.ts b/packages/grpc-js-xds/src/lb-policy-registry/typed-struct.ts
index 6b50d9e83..9ae0b32ee 100644
--- a/packages/grpc-js-xds/src/lb-policy-registry/typed-struct.ts
+++ b/packages/grpc-js-xds/src/lb-policy-registry/typed-struct.ts
@@ -15,6 +15,8 @@
  *
  */
 
+// https://github.com/grpc/proposal/blob/master/A52-xds-custom-lb-policies.md
+
 import { LoadBalancingConfig, experimental } from "@grpc/grpc-js";
 import { LoadBalancingPolicy__Output } from "../generated/envoy/config/cluster/v3/LoadBalancingPolicy";
 import { TypedExtensionConfig__Output } from "../generated/envoy/config/core/v3/TypedExtensionConfig";
diff --git a/packages/grpc-js-xds/src/load-balancer-xds-wrr-locality.ts b/packages/grpc-js-xds/src/load-balancer-xds-wrr-locality.ts
index 5faf8b8e5..8636937fd 100644
--- a/packages/grpc-js-xds/src/load-balancer-xds-wrr-locality.ts
+++ b/packages/grpc-js-xds/src/load-balancer-xds-wrr-locality.ts
@@ -15,6 +15,8 @@
  *
  */
 
+// https://github.com/grpc/proposal/blob/master/A52-xds-custom-lb-policies.md
+
 import { LoadBalancingConfig, experimental, logVerbosity } from "@grpc/grpc-js";
 import { loadProtosWithOptionsSync } from "@grpc/proto-loader/build/src/util";
 import { WeightedTargetRaw } from "./load-balancer-weighted-target";