Merge pull request #215287 from Miskatonic-Electronic/patch-12

Update application-gateway-waf-configuration.md

Author: prmerger-automator[bot]

articles/web-application-firewall/ag/application-gateway-waf-configuration.md

@@ -39,7 +39,7 @@ You can specify an exact request header, body, cookie, or query string attribute
 - **Contains**: This operator matches all request fields that contain the specified selector value.
 - **Equals any**: This operator matches all request fields. * will be the selector value.
 
-In all cases matching is case insensitive. Regular expressions aren't allowed as selectors.
+When processing exclusions, the WAF will perform a case sensitive match for all fields other than request header keys. Depending on your application, the names, and values, of your headers, cookies and query args can be case sensitive or insensitive. Regular expressions aren't allowed as selectors.
 
 > [!NOTE]
 > For more information and troubleshooting help, see [WAF troubleshooting](web-application-firewall-troubleshoot.md).