effective_scope_reducer_managed· reason_code· applies to schema_validationSub-reason for schema_violation when an actor-supplied payload illegally carries `effective_scope` where the object schema reserves that name for a read-only materialized projection. Both surfaces are decided by schema: the create shape bans the member (event-payload.schema.json#/$defs/relation_create_object), and the update shape bans the `effective_scope` / `effective_scope.*` patch paths (#/$defs/relation_update_payload), registered in registry/reducer-managed-path-registry.json. The Event envelope instead requires producer-signed `scope_ref`; the receiver derives the scope from payload and frozen pre-state, verifies exact equality, and only then may copy it into the object's effective_scope projection. See zh/models/circle.md §6.2.