* If no <code>Accept</code> header is sent, the server will use JSON, possibly pretty-printed and annotated.
* If the client sends a <code>Content-Type</code> other than <code>application/json</code> on a POST, PUT or PATCH request, the service will respond with a <code>415</code> (Unsupported Media Type) [[#Error codes and responses|error code]].
* If the client sends invalid JSON, the service will response with a <code>400</code> (Bad Request) HTTP [[#Error codes and responses|error code]] and a descriptive error message within the error object.
Future extension: