Sometimes the question is posed whether Wikipedia allows freedom of speech regarding profanity. Our primary goal is to build an encyclopedia. Freedom of expression is valued, but only to the extent that it does not get in the way of that goal. Including information about offensive material is part of Wikipedia's encyclopedic mission; being offensive is not. We have many articles about profane and sexual subjects—prick, fuck, shit, fart, and so on. Although Wikipedia is not censored, if you were to put profanities on discussion pages, a quick ban might follow. This is especially true for usernames because these show up in many places where people do not want to be bothered by profanity. Repeated off-topic comments on article talk pages also might constitute a breach of policy.
