[Custom Rules] Update block-by-geographical-location.mdx (#24219)

Author: ngayerie

src/content/docs/waf/custom-rules/use-cases/block-by-geographical-location.mdx

@@ -3,12 +3,13 @@ pcx_content_type: configuration
 title: Block traffic by geographical location
 ---
 
-This example custom rule blocks requests by autonomous system number (ASN), continent, or country of origin.
+This example custom rule blocks requests by autonomous system number (ASN), continent, country of origin, or region.
 
-- **Expression**: `(ip.src.asnum eq 131279) or (ip.src.continent eq "AS") or (ip.src.country eq "KP")`
+- **Expression**: `(ip.src.asnum eq 131279) or (ip.src.continent eq "AS") or (ip.src.country eq "KP") or (ip.src.region_code eq "CA")`
 - **Action**: _Block_
 
 ## Other resources
 
 - [Use case: Block traffic from specific countries](/waf/custom-rules/use-cases/block-traffic-from-specific-countries/)
 - [Use case: Allow traffic from specific countries only](/waf/custom-rules/use-cases/allow-traffic-from-specific-countries/)
+- [Fields reference: Geolocation](/ruleset-engine/rules-language/fields/reference/?field-category=Geolocation)