I could tell you about it, but I'll let the post from MythMaps explain:
The ranking system for the Myth 2 server is ready for testing. While the test01 - test40 accounts will still work for this beta test, we're giving you the opportunity to get your own user account for this beta testing period. If you want an account - send an email with your username and password request to: accounts@mythmaps.com and we'll work to get them added as quick as we can. You will not receive any notification that you have been added so you will just need to try logging into the server with your username and password. At this point, we will not be keeping a record of usernames and passwords so if you forget either one, you're on your own. We're finishing up the web-based system for setting up and maintaining accounts and we'll have more news on that as it becomes available. For now, email us and get those account requests in.