diff --git a/docs/installation-and-operations/configuration/README.md b/docs/installation-and-operations/configuration/README.md
index b64d42fb7f..359ab3dfbc 100644
--- a/docs/installation-and-operations/configuration/README.md
+++ b/docs/installation-and-operations/configuration/README.md
@@ -76,6 +76,10 @@ Example:
 
     auth_source_sso:
       header: X-Remote-User
+      
+      # Optional secret to be passed by the header in form
+      # of a colon-separted userinfo string
+      # e.g., X-Remote-User "username:s3cret"
       secret: s3cr3t
       # Uncomment to make the header optional.
       # optional: true