Just in case anybody is as daft as I was and didn't know where to find this option in the admincp after making the changes: it's under the Users category.
I'm not terribly familiar with vB, but fortunately, looking at the code, I was able to find it pretty easily.
Now, onto seeing how it works...
Edit: Did what it said on the box, no problems.
Any chance of adding options? For me, for example, I had a rule about having to have a minimum of 50 posts. It'd be great to have some extra options like that. Oh, I also have a rule about posting more than once in the thread. Is there any way to eliminate doubleposters?
Anyway, thanks a million for your contribution!