diff --git a/README.md b/README.md
index 287bb48..3f17911 100644
--- a/README.md
+++ b/README.md
@@ -43,6 +43,13 @@ inspection UI are implemented. The conflict review UI compares stored local and
 remote field payloads, can apply a stored remote vCard payload, and supports
 manual per-field local/remote merge choices.
 
+API-managed CardDAV credentials are encrypted inside the source record. Source
+deletion physically removes that credential material and records a non-secret
+audit event in the same database transaction; destructive module retirement
+audits every remaining credential before the owning tables are dropped. Legacy
+external references are detached but are never sent to a secret provider for
+deletion because Addresses cannot prove that it owns them.
+
 ## Boundary
 
 `govoplan-addresses` owns:
diff --git a/docs/ADDRESS_MODULE_ARCHITECTURE.md b/docs/ADDRESS_MODULE_ARCHITECTURE.md
index 3ae21c5..fd7ec06 100644
--- a/docs/ADDRESS_MODULE_ARCHITECTURE.md
+++ b/docs/ADDRESS_MODULE_ARCHITECTURE.md
@@ -148,7 +148,12 @@ a conflict instead of silently overwriting remote data. The first conflict
 review UI compares stored local and remote field payloads and can apply a
 stored remote vCard payload or a manual per-field local/remote merge payload.
 Source disconnect/delete removes the source binding and related sync records
-while keeping local contacts.
+while keeping local contacts. Because API-managed CardDAV credentials are
+encrypted in the source row, the same transaction physically removes their
+ciphertext and emits non-secret credential-deletion audit evidence. Destructive
+module retirement audits all remaining owned credential material before table
+removal. An unowned legacy reference is detached rather than passed to an
+external secret provider.
 
 ## Connector Direction