change my mistaken wording to 'control over the serialization of parts of ...

Author: krishahn

versions/3.0.md

@@ -1456,7 +1456,7 @@ requestBody:
               type: '#/components/schemas/Address'
 ```
 
-An `encoding` attribute is introduced to give you more control than boundaries provides over the Content-Type for `multipart` request bodies.  This attribute is _only_ applicable to `multipart/*` and `x-www-form-urlencoded` request bodies.
+An `encoding` attribute is introduced to give you control over the serialization of parts of `multipart` request bodies.  This attribute is _only_ applicable to `multipart/*` and `x-www-form-urlencoded` request bodies.
 
 #### <a name="encodingObject"></a>Encoding Object