diff --git a/docs/pbs/specs/6.1. Intrinsics and Builtin Types Specification.md b/docs/pbs/specs/6.1. Intrinsics and Builtin Types Specification.md
index 7749465a..15dde0dc 100644
--- a/docs/pbs/specs/6.1. Intrinsics and Builtin Types Specification.md	
+++ b/docs/pbs/specs/6.1. Intrinsics and Builtin Types Specification.md	
@@ -30,7 +30,8 @@ This document defines:
 - admissible field types for builtin layouts,
 - intrinsic member metadata and owner inheritance,
 - lowering categories for builtin declarations and members,
-- and the runtime-facing artifact direction for intrinsic operations.
+- the runtime-facing artifact direction for intrinsic operations,
+- and canonical intrinsic registry ownership at ISA/profile boundary.
 
 This document does not define:
 
@@ -105,6 +106,16 @@ reserved top-level `declare const` shell carrying builtin metadata.
 An intrinsic operation is a VM-owned callable behavior with canonical
 definition in the VM contract.
 
+### 5.5 Canonical intrinsic registry artifact
+
+Final intrinsic ids are owned by one canonical ISA-scoped registry artifact.
+
+Rules:
+
+- compiler and runtime consumers must derive final intrinsic ids from that same artifact,
+- dual-authoring of compiler-local and runtime-local intrinsic-id maps is forbidden,
+- strict CI mode must fail on parity mismatch between consumer snapshots and canonical artifact.
+
 ## 6. Reserved Surface Forms
 
 This document temporarily defines the intended source-level shell shape.