406 Not Acceptable
The server cannot produce a response matching the list of acceptable values defined in the request's proactive content negotiation headers.
Explanation
The 406 (Not Acceptable) status code indicates that the server cannot produce a response matching the list of acceptable values defined in the request's proactive content negotiation headers, and the server is unwilling to supply a default representation.
Content negotiation headers include Accept, Accept-Charset, Accept-Encoding, and Accept-Language. When a client includes these headers, they're specifying what types of content they are willing and able to handle. If none of the available representations of the resource meet these criteria, the server responds with a 406 status code.
For example, if a client indicates it can only accept JSON (Accept: application/json), but the server can only provide XML, a 406 response would be appropriate.
Example Response
HTTP/1.1 406 Not Acceptable Content-Type: text/plain 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.
Related Status Codes
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