After creating or updating an entry, the server may include the representation of the entry in its response.
This is helpful in implementations in which the server annotates the entry with various extensions or attributes that the client doesn't provide. It is a useful optimization over having the client issue another request to the URL in the response's Location header to retrieve the annotated entry.
Based on protocol-08:
In Section 5.2, to the end of:
2. If the Member resource was created successfully, the server responds with a status code of 201 and a Location: header that contains the URI of the newly created resource.
If the server includes a body in the response, the body MUST be the representation of the newly-created resource.
In Section 5.3.2, to the end of:
2. Upon a successful update of the resource the server responds with a status code of 200.
If the server includes a body in the response, the body MUST be the representation of the updated resource.
Entry-creation/modification response bodies may contain information that clients should be aware of.