There is a profanity filter that has words that are entered into it. The words that are considered acceptable use what is called "The Prime Time Rule." If it is commonly used on prime time TV, it is considered acceptable by the majority of people. I don't agree with letting some of the words through but it is not my site. Some words as you expressed can be used different way (female dog) and in one particular case, it is totally unacceptable. In a couple of other ways, it is, ie, something is extremely difficult or to complain about something. The filter does not know the difference so it kills the word.

The bad thing about the filter is that it cannot determine if a word is being deliberately misspelled to avoid the filter. This is very common in some forums. Quite often words get by the filter. For instance, if the word "shirt" were in the filter, someone would type "sh1rt" or "sh*rt" and it would pass the filter. You get the idea. The problem with that, though, is that it does not pass the moderator filter. That kind of thing is frowned on severely by moderators.