http://www.rfc-editor.org/rfc/rfc7694.txt
RFC 7694: Hypertext Transfer Protocol (HTTP) Client-Initiated Content-Encoding, J. Reschke2015-11-01T23:00:00-00:00Content 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.