Merge pull request #288082 from Miskatonic-Electronic/patch-40

Update waf-front-door-drs.md

Author: prmerger-automator[bot]

articles/web-application-firewall/afds/waf-front-door-drs.md

@@ -69,7 +69,9 @@ The version of the DRS that you use also determines which content types are supp
 
 DRS 2.1 rules offer better protection than earlier versions of the DRS. It includes other rules developed by the Microsoft Threat Intelligence team and updates to signatures to reduce false positives. It also supports transformations beyond just URL decoding.
 
-DRS 2.1 includes 17 rule groups, as shown in the following table. Each group contains multiple rules, and you can customize behavior for individual rules, rule groups, or an entire rule set. For more information, see [Tuning Web Application Firewall (WAF) for Azure Front Door](waf-front-door-tuning.md).
+DRS 2.1 includes 17 rule groups, as shown in the following table. Each group contains multiple rules, and you can customize behavior for individual rules, rule groups, or an entire rule set. DRS 2.1 is baselined off the Open Web Application Security Project (OWASP) Core Rule Set (CRS) 3.3.2 and includes additional proprietary protections rules developed by Microsoft Threat Intelligence team.
+
+For more information, see [Tuning Web Application Firewall (WAF) for Azure Front Door](waf-front-door-tuning.md).
 
 > [!NOTE]
 > DRS 2.1 is only available on Azure Front Door Premium.