https://www.phpbb.com/kb/article/custom ... mmer-tool/
Thanks for the links, Verhaden. I'll pass them along to our site Admin over at Unseen Servant, too, in case he doesn't have them in place.
We've instituted a "verification" process there, as well. Anytime a new user ID is created, a Moderator or Admin has to approve the first two posts before they become visible to anyone else. Then the Admin adds that name to a Safe list. So even when those wily spam bastards figure out how to get past the filters, the only people who have to see the junk postings is the moderators.