When I was joining a friend to play on the prophunt server, I got perma-banned for my name. I joined earlier with the same name and it let me in.
INFO:
Name - Sekzual Taigur
Steam ID - STEAM_0:1:18933923

You are only banned when the name isn't valid.

It can't be that you joined our server earlier with the same exact name.

If you disagree, please post evidence such as console output or a screen of the console.

Fix your name and we will unban you.

If you do not fix your name and rejoin after the unban, you will just be banned again.

Thanks,
-coolz