CD-Key ban? (mat) please help

[elgeorge86]

I have just checked the chat monitor.bw ban list and have seen my name and my friends together, we both have (mat) after our name.
What does (mat) mean? and how long will this ban last? we have advertised our game a little bit but we have not used any foul language in the main chat, it would be good to give a reason behind the ban or notes.
Why is there no filter in the chat anyway, this would be a simple solution to stop ban occuring from swearing very naive to be the only game not to implement one.