diff --git a/config/gitlab.yml.example b/config/gitlab.yml.example
index 41d5a13208..bc1ac5319a 100644
--- a/config/gitlab.yml.example
+++ b/config/gitlab.yml.example
@@ -116,6 +116,7 @@ production: &base
 
     # Filter LDAP users
     #
+    #   Format: RFC 4515
     #   Ex. (employeeType=developer)
     #
     user_filter: ''