It would be great if admins had a way to tag the "low-quality" comments that triggered the rate limiting, so people can kind of learn by example. Like "Please slow down and stop posting things such as <link>, <link>, and <link>."

This rate limiting seems to happen to me quite a bit, and when I've E-mailed, it's "Hmm, you look like you're posting fine now. We'll remove the limit." Leaving me scratching my head, searching in vain through my comment history for anything that might have plausibly triggered the action.