There are discussions/code examples using old ULX code where filters were made.
You understand the difficulty in this, right?
In theory, its a good thing.
Unfortunately, in practice, it's usually not.
In many cases, when someone wishing to cause trouble realizes a straight spelled word is censored, say the word 'poop' thats spelled with an S, they then start trying every ascii combination that might look/be like the original normal spelling. s41t for instance. They then spend the next few minutes annoying other players who might want family friendly atmosphere.
If you start adding every other spelling of that word into your filters, well, by then, you have more lag for everything said than you do actual conversation.
Found this ... Jay was tinkering long ago.
http://forums.ulyssesmod.net/index.php/topic,3339.msg10149.html#msg10149