Q: Header for HTTP/1 compression in PUT / POST request When receiving gzipped data for a HTTP GET request the response header shows this by the field Content-Encoding. What is the correct way in a HTTP POST / HTTP PUT request to indicate what the request is sending gzipped data?
According to https://en.wikipedia.org/wiki/List_of_HTTP_header_fields the request header does not know the Content-Encoding field. So how does the receiver know which compressing method is used? 

A: Content-Encoding is both a request and response header field, and gzip content encoding can indeed be used both in requests and responses. And yes, it may fail in requests if the server doesn't process the header field correctly. (That would be a bug in the server, though).
Further reading: https://httpwg.org/specs/rfc7694.html
