2.2.6.5 XML Format
The data service URI addressing scheme, specified in URI Format: Resource Addressing Rules (section 2.2.3), enables the constituent parts of an EntityType and associations between EntityTypes to be identified directly. This allows interaction with a specific piece of data or relationship, independent of the rest of the EntityType. Servers responding to requests that identify a constituent part of an EntityType instance MUST respond with an XML-based serialization of that part's value, as specified in this section, unless the request URI's resource path ends in "$value" (in which case it is to use the format defined in Raw Format (section 2.2.6.4)).
The serializations defined in the following subsections MUST be identified with the application/xml media type or text/xml media types.