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

PROPOSED STANDARD · November 2015 · J. Reschke

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.

Not ingested in full here — read it on rfc-editor.org.