Add more context

Author: maxvp

src/content/docs/cloudflare-one/policies/gateway/dns-policies/common-policies.mdx

@@ -70,15 +70,15 @@ The categories included in this policy are not always a security threat, but blo
 
 ## Block a dynamic list of categories
 
-You can block a set of categories sent in the [EDNS](https://datatracker.ietf.org/doc/html/rfc6891) portion of a request with the [Request Context Categories](/cloudflare-one/policies/gateway/dns-policies/#request-context-categories) selector. The category ID list to block on can be sent to the gateway DNS as JSON using OPT code `65050`. For example:
+You can add a list of category IDs to the [EDNS header](https://datatracker.ietf.org/doc/html/rfc6891) of a request sent to Gateway as a JSON object using OPT code `65050`. For example:
 
 ```json
 {
 	"categories": [2, 67, 125, 133]
 }
 ```
 
-This is useful to filter by categories that are not known at the time of creating a rule. When a DNS request is blocked because of the request context categories, Gateway will reply with an EDE Blocked(15) field containing an array of the matched categories.
+With the [Request Context Categories](/cloudflare-one/policies/gateway/dns-policies/#request-context-categories) selector, you can block the category IDs sent with EDNS. This is useful to filter by categories not known at the time of creating a policy, or to enforce device-specific DNS content filtering without reaching your account limit. When Gateway uses this selector to block a DNS query, Gateway will return an Extended DNS Error (EDE) Code 15 - Blocked error, along with a field containing an array of the matched categories.
 
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