Arachnakid
If the people who post the one-liners and smilies are just looking for attention, I think the last thing you should do is give it to them by PMing them or responding to their comments. If they post something relevant to the discussion, then acknowledge this and include them. If they post something random or unintelligent, ignore them. Sooner or later, they will either figure out that they will get more attention by actually participating, or leave to annoy people in another forum. If they don't get a response from their actions, they will get bored and stop doing it. I agree that some one-liners can actually further discussion, but if that is the case then most of the people in the topic should easily be able to tell the difference.
That
does work in some cases--ignoring problem posters. But the thing is, not everyone is capable of catching on when they're not wanted. People posting stupid things in some desperate sort of persistence can be even more annoying than someone just dropping a completely irrelevant one-liner.
Plus, if you have this many people already ignoring rules that were clearly stated, how could any sort of "ignore and let die" policy be set up when it's so much more vague than the set rules?
In the cases of spamming threads, the ignoring idea is very effective. But for repeated offenses, some sort of notification
should be given (in my opinion at least.)
Besides, if I'd done something wrong, I know I'd much rather have it brought to my attention so I could fix it, rather than being left in angsty uncertainty.