One distinctive feature of modern Russian language is that profanities are not used simply to emphasize normal language, but in most use cases substitute core words in sentences and bring a meaning of their own. I've seen many exchange students struggling to understand casual Russian dialogs containing мат, though their grasp of spoken language was satisfactory or even good.
The question here - should we allow the questions regarding origins, meaning and proper use of Russian profanities? If there are 500-pages dictionaries dedicated simply to мат, doesn't it mean that we should dedicate time to questions regarding it?