The way it is now is great. You see, it's not so much a rule as giving mod the ability to delete those posts if they really want to. It's more of a way to stop spam that isn't entirely spam. But since you can't describe what ifs in a set of rules, letting a mod decide independently can work very well. I don't see a problem with how we're doing it now.
It's not specifically against the rules. We have been deleting posts on account that they're really just spam, but no where in the rules does it say you have to have more then one word in your post