diff --git a/11.md b/11.md
index a8c9c530..828e1a20 100644
--- a/11.md
+++ b/11.md
@@ -22,7 +22,7 @@ When a relay receives an HTTP(s) request with an `Accept` header of `application
 }
 ```
 
-Any field may be omitted, and clients MUST ignore any additional fields they do not understand.
+Any field may be omitted, and clients MUST ignore any additional fields they do not understand. Relays MUST accept CORS requests by sending `Access-Control-Allow-Origin`, `Access-Control-Allow-Headers`, and `Access-Control-Allow-Methods` headers.
 
 Field Descriptions
 -----------------