If multiple encodings have been applied to an entity, the ContentEncodings must be listed in the order in which they were applied. All content-coding values are case-insensitive. Clients MAY apply content encodings to the body in requests. A server MAY apply content encodings to the bodies in responses. The server MUST only use encodings listed in the Accept-Encoding header field in the request. If the server is not capable of decoding the body, or does not recognize any of the content-coding values, it must send a UNSUPPORTED_MEDIA_TYPE Response, listing acceptable encodings in an AcceptEncodingHeader.