Hypertext Transfer Protocol (HTTP) Client-Initiated Content-Encoding
RFC 7694

Received changes through RFC Editor sync (changed abstract to 'In HTTP, content codings allow for payload encodings such as for compression or integrity checks. In particular, the "gzip" content coding is widely used for payload data sent in response messages.

Content codings can be used in request messages as well; however, discoverability is not on par with response messages. This document extends the HTTP "Accept-Encoding" header field for use in responses, to indicate the content codings that are supported in requests.')