I was looking for a suitable tag for [a question about the email headers my email server creates](http://serverfault.com/questions/759695/why-does-my-server-hostname-appear-in-exim-email-headers-sent-from-a-different-d)  but while looking I noticed that header-related tags could probably do with a clean-up:

[![enter image description here][1]][1]

I'm sure there shouldn't be [tag:header] and [tag:headers] as separate tags.  
Two people follow [tag:headers], so maybe [tag:header] should be merged into it, but should there be any generic [tag:headers] tag at all, is it possible to be an expert on headers in general or is there something more appropriate?

Do we need [tag:host-headers] and [tag:requestheader]? 

  [1]: https://i.sstatic.net/yrwuR.png