The profanity filter is based on a list of words we deem unsuitable for a civil discussion - these words get replaced with stars (****) even when part of longer words - for example, "assist" used to be "***ist". We do, however, have a whitelist of words that we continuously improve by adding words that shouldn't be filtered. If you see any words filtered that shouldn't be filtered (f.e. "assist"), we would appreciate it if you sent them to me and we'll add them to the whitelist.