Add a note on dnsrewrite limitations

docs/general/dns-filtering-syntax.md

@@ -169,6 +169,14 @@ Client names usually contain spaces or other special characters, which is why yo
 
 - `||example.org^$client=192.168.0.0/24`: block `example.org` for all clients with IP addresses in the range from `192.168.0.0` to `192.168.0.255`.
 
+:::info
+
+If you are maintaining a blocklist that is included in AdGuard DNS and AdGuard Home (i.e. included into [HostlistsRegistry][hostlistsregistry]), `$dnsrewrite` rules will be automatically filtered out. If these rules are required for your blocklist, please request permission by opening a new issue in the [HostlistsRegistry][hostlistsregistry] repo.
+
+:::
+
+[hostlistsregistry]: https://github.com/AdguardTeam/HostlistsRegistry
+
 #### `denyallow` {#denyallow-modifier}
 
 You can use the `denyallow` modifier to exclude domains from the blocking rule. To add multiple domains to one rule, use the `|` character as a separator.