Update docs/API requests.md

Co-authored-by: jonathan-r-thorpe <[email protected]>

docs/API requests.md

@@ -159,7 +159,7 @@ The body of the request MUST include an object which includes an `arguments` obj
 }
 ```
 
-A successful response MUST be of type [NcMethodResult](https://specs.amwa.tv/ms-05-02/latest/docs/Framework.html#ncmethodresult). If the request encountered an error then the response result returned MUST inherit from [NcMethodResultError](https://specs.amwa.tv/ms-05-02/latest/docs/Framework.html#ncmethodresulterror) and include an errorMessage of type [NcString](https://specs.amwa.tv/ms-05-02/latest/docs/Framework.html#primitives).
+A successful response MUST be of type [NcMethodResult](https://specs.amwa.tv/ms-05-02/latest/docs/Framework.html#ncmethodresult). If the request encountered an error then the response MUST either be of the type, or inherited from the type, [NcMethodResultError](https://specs.amwa.tv/ms-05-02/latest/docs/Framework.html#ncmethodresulterror) and include an errorMessage of type [NcString](https://specs.amwa.tv/ms-05-02/latest/docs/Framework.html#primitives).
 
 This is equivalent to invoking the specified method.