diff --git a/api/app/Enums/Observability/ActorType.php b/api/app/Enums/Observability/ActorType.php
index 1fd6c7ac..95804b05 100644
--- a/api/app/Enums/Observability/ActorType.php
+++ b/api/app/Enums/Observability/ActorType.php
@@ -15,20 +15,19 @@ use Illuminate\Http\Request;
  *  1. Portal-token request → PORTAL_TOKEN
  *  2. Authenticated super_admin → SUPER_ADMIN
  *  3. Authenticated org_admin → ORGANIZER_ADMIN
- *  4. Other authenticated user → ORG_MEMBER (covers volunteers — Crewli has
- *     no `volunteer` Spatie role today; volunteers join an organisation as
- *     org_member with org-pivot semantics. Promote to a dedicated case once
- *     the role model differentiates them at the user level.)
+ *  4. Other authenticated user → ORG_MEMBER
  *  5. None of the above → UNAUTHENTICATED
  *
- * The VOLUNTEER case is reserved for that future split.
+ * Crewli has no dedicated `volunteer` Spatie role today; volunteer-ness is
+ * behaviour (a user has shift assignments) rather than identity. A
+ * dedicated VOLUNTEER actor_type case will land alongside that role split
+ * if/when it is introduced (BACKLOG OBS-1).
  */
 enum ActorType: string
 {
     case ORGANIZER_ADMIN = 'organizer_admin';
     case SUPER_ADMIN = 'super_admin';
     case PORTAL_TOKEN = 'portal_token';
-    case VOLUNTEER = 'volunteer';
     case ORG_MEMBER = 'org_member';
     case UNAUTHENTICATED = 'unauthenticated';
 
diff --git a/api/tests/Feature/Observability/BindSentryContextTest.php b/api/tests/Feature/Observability/BindSentryContextTest.php
index c9c201c2..ecda8981 100644
--- a/api/tests/Feature/Observability/BindSentryContextTest.php
+++ b/api/tests/Feature/Observability/BindSentryContextTest.php
@@ -140,9 +140,8 @@ final class BindSentryContextTest extends TestCase
 
     public function test_org_member_authenticated_user_tags_actor_type_org_member(): void
     {
-        // Crewli has no `volunteer` Spatie role today; volunteers fall into
-        // org_member. The VOLUNTEER ActorType case is reserved for a future
-        // split — see ActorType::resolve() docblock.
+        // Volunteer-ness is behaviour in Crewli (shift assignments), not
+        // identity — non-admin authenticated users resolve to ORG_MEMBER.
         $user = User::factory()->create();
         $user->assignRole('org_member');