I’d like to add one more Rool to “da Roolz” list, and one that isn’t onerous. In fact it’s quite simple: please do not make any comments that consist only of a link. That is often puzzling, because we don’t know why you’re putting up such a link. Is it because you agree with it, because it demonstrates a phenomenon we’re discussing, or do you just want to amuse us?
And do read Da Roolz (rules for commenting) if you haven’t before. They’re on the sidebar, or here. They’re de rigueur for new readers who want to join the discussion.
I’ve added the new one.