diff --git a/.changeset/28855-object-extension-registry-comment.md b/.changeset/28855-object-extension-registry-comment.md
new file mode 100644
index 00000000000..d1b7d577159
--- /dev/null
+++ b/.changeset/28855-object-extension-registry-comment.md
@@ -0,0 +1,10 @@
+---
+'@objectstack/spec': patch
+---
+
+docs(spec): the `object_extension` registry row's comment now says what happens to a code package's `objectExtensions`
+
+Clause-②: no
+Metadata-protocol: none
+
+The `//` comment above the `object_extension` row of `DEFAULT_METADATA_TYPE_REGISTRY` (`src/kernel/metadata-plugin.zod.ts`, which ships in the package) said the artifact loader stores a code package's `objectExtensions` under this type. It does not: the ObjectQL engine's `registerApp` registers each extension as an `'extend'` contributor of its target object, and the artifact loader files no item from that collection because an extension carries `extend` and no `name`. The comment now says so, and that this type's items are the stored rows the `/api/v1/meta` doors write. Comment only: no key, row field or schema changes.
diff --git a/packages/spec/src/kernel/metadata-plugin.zod.ts b/packages/spec/src/kernel/metadata-plugin.zod.ts
index fe888e6be29..bf890d60745 100644
--- a/packages/spec/src/kernel/metadata-plugin.zod.ts
+++ b/packages/spec/src/kernel/metadata-plugin.zod.ts
@@ -817,8 +817,12 @@ export const DEFAULT_METADATA_TYPE_REGISTRY: MetadataTypeRegistryEntryParsed[] =
   // `filePatterns`: the `*.extension.ts` convention a code package's
   // `defineObjectExtension` files follow (`examples/app-showcase/src/data/
   // extensions/`). A code package declares its extensions in
-  // `objectExtensions`, which the artifact loader already stores under this
-  // type name. `supportsOverlay` /
+  // `objectExtensions`, and they are never stored as items of this type: the
+  // ObjectQL engine's `registerApp` registers each one as an `'extend'`
+  // contributor of its target object. The artifact loader maps that collection
+  // to this type name but files no item from it, because an extension carries
+  // `extend` and no `name`. This type's items are the stored rows the
+  // `/api/v1/meta` doors write. `supportsOverlay` /
   // `allowEnvironmentOverlay: false`: an extension is never overlaid; a
   // package changes its own item, and a second package writes a second item.
   // The body is judged by the metadata-protocol doors with