meaning of 'cool' in this context

[minemax]

I'd like to know what 'cool' means in this context (taken from a web-forum):

Rules for new posters:
So from now on everyone, before you make each post, just ask yourself: "Is my life worth living?"
If the answer is no, please kill yourself.
If the answer is yes, now ask yourself this question: "Does my post contain correct spelling, grammar and punctuation?"
If the answer is no, please kill yourself.
If the answer is yes, now ask yourself this question: "Does my post consist of more than a single smilie, contain more than 5 words, and does it contribute to the discussion?"
If the answer is yes, then you are free to post. If the answer is no, but you are cool, you are free to post. If the answer is no and you are not cool, please kill yourself.

Thanks.

[Ouisch]

"Please kill yourself"?? What a friendly message board! (Not!)

Anyway, their basic rules for posting ask that if you post a message, it should be more than two or three words long. You should also only use one smiley at a time, and use proper spelling and grammar. If you're not going to abide strictly by those rules, but you still have something interesting or constructive to contribute to the discussion ("if you're cool"), then they won't mind as much if you post short or misspelled messages. If you are a "troll" - someone who intrudes on message boards with the intent on breaking their rules and just posting nonsense or inflammatory messages, then you are not cool, and you are not welcome to bend their rules or to even post on their boards.