There was a BBS package in the 80s that had language moderation as a default feature. The sysop could choose whether the BBS should refuse to post a message that included the word "shit" for instance. It was configurable, but not easily.
A friend ran a BBS on behalf of a winery in Napa Valley. But she kept having trouble with a few of the forum sections. After some debugging, it turned out that the software looked at "chardonnay" and saw "cHARDONnay"... and "hardon" was in its list of bad words.