I just stumbled across this question:
Is it still an acceptable thing to use custom header fields and if yes how should they be named?
As far as i knew custom fields start with an X-.. but according to RFC 6648 these are depricated since 2012 but I also haven't found any proposals for alternatives from them.
So would it make sense to name custom fields just "normal" (without an X-Prefix)? Does it makes sense at all to use custom fields for exchanging additional information?