Improve item occurrence holder corrections

docs/internal/dnd.md

@@ -201,6 +201,13 @@ hashes, validator module keys, or reason codes. Those identifiers remain in
 ordinary validation provenance; only the actionable semantic guidance is
 eligible for the correction prompt.
 
+Item-occurrence shape validation groups repeated holder mistakes by occurrence
+kind and gives the producer the required JSON null/non-null relationship. It
+identifies affected records by contextual item name and cited transcript range,
+never by the deterministically attached durable item ID. Holder mistakes remain
+semantic rejections rather than silent rewrites because changing a holder can
+also change the meaning of the occurrence kind.
+
 Enemy-event extraction additionally rejects a second `engaged` observation for
 the same comparison identity within one scene-scoped result. Normalization may
 combine results from distinct scenes, so it intentionally does not apply that