My rule of thumb is:
If the most anal retentive, prudish Nun you can possibly imagine wouldn't say it, it's definately going to get you muted.
Also, any acronym or 'creative spelling' of anything in that category will also get you at least warned if not muted.
Of course, I routinely violate this rule, even knowing it, and routinely get warned and muted. But, not before I get to say something really funny and make people laugh.
Zazen