diff --git a/css-contain-3/Overview.bs b/css-contain-3/Overview.bs
index ee1269815a8..ba4dfde1b8e 100644
--- a/css-contain-3/Overview.bs
+++ b/css-contain-3/Overview.bs
@@ -493,6 +493,7 @@ Naming Query Containers: the 'container-name' property</h3>
 	<dt><dfn><<custom-ident>></dfn>
 	<dd>
 		Specifies a [=query container name=] as an [=identifier=].
+		The keywords ''container-name/none'', ''and'', ''not'', and ''or'' are excluded from this <<custom-ident>>.
 	</dl>
 
 	<div class=example>