Some FAQ: (you need an account to see links)

And this comes up a lot, so I'm just gonna retell y'all this.

If you try to create an account and get an error when you enter the email, that means the account's been purged but it's not available for creation yet. Sometimes it'll stop you on the first step, sometimes it'll let you by and give you that error on step three.
/~John says "All usernames from the most recent purge are glitched and will probably never be available for creation. Every response TNT has made to my tickets has been unhelpful and purposely vague. It might help if you sent in a suggestion to the Editorial asking them to fix purged usernames. "

I asked snarkie about the purge. Not helpful at all.

Screenshots: