Note scan result policy feature

doc/user/project/protected_branches.md

@@ -43,6 +43,9 @@ When a branch is protected, the default behavior enforces these restrictions on
    for that branch at the project level are ignored. All other protections continue
    to use project level settings.
 
+You can implement a [scan result policy](../application_security/policies/scan-result-policies.md#approval_settings)
+to prevent protected branches being unprotected or deleted.
+
 ### When a branch matches multiple rules
 
 When a branch matches multiple rules, the **most permissive rule** determines the