The 406 status may be used in response to restrictions sent with the user's request (set in the Accept, Accept-Charset, Accept-Encoding, Accept-Language or Accept-Ranges header fields).
HTTP status: 406 Not acceptable
HTTP headers: Standard content delivery headers only are required for this situation
Content element to contain the following text:
Your browser preferences indicate that available versions of this content are not acceptable
An optional custom message can be included here.
Please contact us if you require further assistance with your request.
Note: It may seem counter-intuitive that often in order to send this Not acceptable message, content must be sent that is not acceptable due the same accept request headers. The HTTP specification addresses this concern:
HTTP/1.1 servers are allowed to return responses which are not acceptable according to the accept headers sent in the request. In some cases, this may even be preferable to sending a 406 response.