diff --git a/docs/source/markdown/options/creds.md b/docs/source/markdown/options/creds.md
index 9e425264c9..d88cf4a189 100644
--- a/docs/source/markdown/options/creds.md
+++ b/docs/source/markdown/options/creds.md
@@ -7,3 +7,8 @@
 The [username[:password]] to use to authenticate with the registry, if required.
 If one or both values are not supplied, a command line prompt will appear and the
 value can be entered. The password is entered without echo.
+
+Note that the specified credentials are only used to authenticate against
+target registries.  They are not used for mirrors or when the registry gets
+rewritten (see `containers-registries.conf(5)`); to authenticate against those
+consider using a `containers-auth.json(5)` file.