Should response Content-Type always be same as Accept?
<p>I have a resource with an original version of the entity format and a later, improved version with breaking changes.</p>

<p>The caller opts into later versions using the <code>Accept</code> header.</p>

<p>Pretend for a moment that my service only returns JSON.</p>

<p>Should the response be <code>application/json</code> or exactly the format in the <code>Accept</code> header? Does anyone care if I cheat?</p>

<p>For example, is this good or bad:</p>

<ul>
<li>Client request: <code>GET /people/1; Accept: application/vnd.personv2+json</code></li>
<li>Server response: <code>200 { "Name": "John" }; Content-Type: application/json</code></li>
</ul>

<p>The server has presented a v2 person format using JSON, but has said that its "just" normal application JSON, as opposed to saying its exactly the format requested.</p>