title: What is the proper REST response code for a valid request but an empty data?
body: <p>For example you run a GET request for <code>users/9</code> but there is no user with id #9.
  Which is the best response code?</p>
  
  <ul>
  <li>200 OK</li>
  <li>202 Accepted</li>
  <li>204 No Content</li>
  <li>400 Bad Request</li>
  <li>404 Not Found</li>
  </ul>