We have a bug, in that we interpret certain conditions as 415 (Unsupported media type).
415 is "Unsupported media type"
The server is refusing to service the request because the entity of the request is in a format not supported by the requested resource for the requested method.
I read this as "if the client POSTs an entity that the server cannot handle, send a 415 error".
We're currently using 415 in content-negotiation, when we receive an Accept header that we cannot satisfy. In this scenario, we should respond with 406 Not Acceptable:
The resource identified by the request is only capable of generating response entities which have content characteristics not acceptable according to the accept headers sent in the request.
See www.w3.org/Protocols/rfc2616/rfc2616-sec10.html for HTTP response-code explanations.
