I've looked in a lot of places, but none have all the header tags you can use.
There are meta tags:
Content-type
Expires
keywords
description
author
ROBOTS
and Rev tags
and Rel tags
and Http-Equiv tags
Post more meta, rel, rev and other header tags! The goal is a 10Kb header!
Last minute edit:
While looking for these, I actually found this incredibly large page with, I think, everything tag there is for meta, rel, rev, and http-equiv.
http://vancouver-webpages.com/META/