I'm experimenting with this. Basically, if you get a mute you will not be able to post on alliance boards or rename your armies.
Reason: We find that every time someone is muted they tend to lash out in any way that they can. First they use the help desk (as they should) and then they extend into the game. They go to alliance boards and give some deranged version of the incident and/or they rename their armies to stuff like "ihatestaff"...