This is your login and it also forms your unique profile URL, eg:
www.crawlofthedead.com/zombies/your_username

This is the name that will appear on your profile.
If you leave this field blank, your screen name will be the same as your username.

If you're trying to register and don't know the answer to these zombie related questions below, sorry - but there has been a relentless attack by spammers on the site for some time and I've had to basically put these barriers up :(
There are a number of questions, if you refresh you'll get a different one. If I had more time to maintain the site, I would - but life is hectic.