add waf

Author: halkazwini

articles/web-application-firewall/afds/waf-front-door-configure-custom-response-code.md

@@ -11,7 +11,7 @@ ms.custom: devx-track-azurepowershell
 
 # Configure a custom response for Azure Web Application Firewall
 
-By default, when Azure Web Application Firewall blocks a request because of a matched rule, it returns a 403 status code with the message "The request is blocked." The default message also includes the tracking reference string that's used to link to [log entries](./waf-front-door-monitor.md) for the request.
+By default, when Azure Web Application Firewall (WAF) blocks a request because of a matched rule, it returns a 403 status code with the message "The request is blocked." The default message also includes the tracking reference string that's used to link to [log entries](./waf-front-door-monitor.md) for the request.
 
 In this article, you learn how to configure a custom response status code and a custom message with a reference string for your use case using the Azure portal, PowerShell, or the Azure CLI.