diff --git a/docs/content/https/tls.md b/docs/content/https/tls.md
index 40d0585b4..9b1023386 100644
--- a/docs/content/https/tls.md
+++ b/docs/content/https/tls.md
@@ -428,6 +428,7 @@ metadata:
 
 spec:
   clientAuth:
+    # the CA certificate is extracted from key `tls.ca` of the given secrets.
     secretNames:
       - secretCA
     clientAuthType: RequireAndVerifyClientCert