Is there any reason that the entries x-dns-prefetch-control and x-ua-compatible should not be removed? They do not meet the requirements for inclusion per the spec. at this stage:
Such extensions must use a name that is identical to an HTTP header registered in the Permanent Message Header Field Registry…
Hixie: If they are implemented by software, the solution is to fix the IANA registry, not this one.
Theimp: When that's done, they can be re-added.