406 Not Acceptable

The HyperText Transfer Protocol (HTTP) 406 Not Acceptable client error response 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 that the server is unwilling to supply a default representation.

Proactive content negotiation headers include:

• Accept
• Accept-Encoding
• Accept-Language

If a server returns such an error status, the body of the message should contain the list of the available representations of the resources, allowing the user to choose among them.

406 Not Acceptable