diff --git a/config/settings/base.py b/config/settings/base.py
index 6197fec6..ca40a803 100644
--- a/config/settings/base.py
+++ b/config/settings/base.py
@@ -131,8 +131,7 @@
     {
         "NAME": "django.contrib.auth.password_validation.MinimumLengthValidator",
         "OPTIONS": {
-            # TODO: passer à 12
-            "min_length": 9,
+            "min_length": 12,
         },
     },
     {
diff --git a/dora/orientations/admin.py b/dora/orientations/admin.py
index 0b938e82..6775ccbb 100644
--- a/dora/orientations/admin.py
+++ b/dora/orientations/admin.py
@@ -32,6 +32,16 @@ class OrientationAdmin(admin.ModelAdmin):
         "prescriber_structure",
         "service",
     )
+    readonly_fields = ("service", "di_service")
+    search_fields = (
+        "beneficiary_last_name",
+        "beneficiary_email",
+        "referent_last_name",
+        "referent_email",
+        "original_service_name",
+        "di_structure_name",
+        "di_service_name",
+    )
     date_hierarchy = "creation_date"
     ordering = ("-id",)
     readonly_fields = ("query_id", "query_expires_at", "original_service_name")
diff --git a/dora/orientations/migrations/0010_orientation_check_valid_service.py b/dora/orientations/migrations/0010_orientation_check_valid_service.py
new file mode 100644
index 00000000..27e75a3d
--- /dev/null
+++ b/dora/orientations/migrations/0010_orientation_check_valid_service.py
@@ -0,0 +1,29 @@
+# Generated by Django 4.2.12 on 2024-07-15 16:53
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("orientations", "0009_orientation_query_expires_at_and_more"),
+    ]
+
+    operations = [
+        migrations.AddConstraint(
+            model_name="orientation",
+            constraint=models.CheckConstraint(
+                check=models.Q(
+                    models.Q(
+                        ("service", None),
+                        models.Q(("di_service_id", ""), _negated=True),
+                    ),
+                    models.Q(
+                        models.Q(("service", None), _negated=True),
+                        ("di_service_id", ""),
+                    ),
+                    _connector="OR",
+                ),
+                name="check_valid_service",
+            ),
+        ),
+    ]
diff --git a/dora/orientations/models.py b/dora/orientations/models.py
index ff7643a4..555ca621 100644
--- a/dora/orientations/models.py
+++ b/dora/orientations/models.py
@@ -172,6 +172,18 @@ class Orientation(models.Model):
     )
     last_reminder_email_sent = models.DateTimeField(blank=True, null=True)
 
+    class Meta:
+        constraints = (
+            # service lié à l'orientation : DORA ou D·I, mais pas les deux
+            models.CheckConstraint(
+                check=(
+                    (models.Q(service=None) & ~models.Q(di_service_id=""))
+                    | (~models.Q(service=None) & models.Q(di_service_id=""))
+                ),
+                name="check_valid_service",
+            ),
+        )
+
     def save(self, *args, **kwargs):
         if not self.id:
             self.original_service_name = self.get_service_name()
diff --git a/dora/structures/migrations/0071_structure_putative_members.py b/dora/structures/migrations/0071_structure_putative_members.py
new file mode 100644
index 00000000..10a6cce1
--- /dev/null
+++ b/dora/structures/migrations/0071_structure_putative_members.py
@@ -0,0 +1,23 @@
+# Generated by Django 4.2.12 on 2024-07-15 13:45
+
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ("structures", "0070_alter_structure_phone"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="structure",
+            name="putative_members",
+            field=models.ManyToManyField(
+                related_name="putative_structure_set",
+                through="structures.StructurePutativeMember",
+                to=settings.AUTH_USER_MODEL,
+            ),
+        ),
+    ]
diff --git a/dora/structures/models.py b/dora/structures/models.py
index b388c7ce..ace177af 100644
--- a/dora/structures/models.py
+++ b/dora/structures/models.py
@@ -278,6 +278,9 @@ class Structure(ModerationMixin, models.Model):
     data_inclusion_source = models.TextField(blank=True, db_index=True)
 
     members = models.ManyToManyField(User, through=StructureMember)
+    putative_members = models.ManyToManyField(
+        User, through=StructurePutativeMember, related_name="putative_structure_set"
+    )
 
     disable_orientation_form = models.BooleanField(default=False)
 
diff --git a/dora/users/apps.py b/dora/users/apps.py
new file mode 100644
index 00000000..f9fac63a
--- /dev/null
+++ b/dora/users/apps.py
@@ -0,0 +1,6 @@
+from django.apps import AppConfig
+
+
+class UsersConfig(AppConfig):
+    name = "dora.users"
+    verbose_name = "utilisateurs"