A million years ago (in Internet years), [Jeff put a tag blacklist in place](http://meta.askubuntu.com/questions/985/blacklist-the-linux-tag#comment2478_987) to stop people tagging things with `linux` or `unix`. Probably makes sense but I think his regex was bum:

    ^linux|unix$

I suspect (though it's been a while since I've meddled with .NET regexes) that  it's interpreted as:

> begins with `linux` *or* ends with `unix`

[Regex Storm agrees with my interpretation][1]. Again, I don't think this was the original aim here.

Why is this a problem? Well I've just tried to tag something as `linux-headers` (a real package in Ubuntu) and a pretty important one if you're compiling stuff against the kernel. Of course there are flowery alternative I could pick (or create), but I just don't see why this is blocked.

TL;DR: I think we need the regex updating to:

    ^(linux|unix)$


  [1]: http://regexstorm.net/tester?p=%5Elinux%7Cunix%24&i=linux-headers%0D%0Alinux%0D%0Anot-linux%0D%0Aunix-sucks%0D%0A&o=im