Be reasonable and keep conversation interesting!
We understand humor of all sorts, but don't excessively attack or belittle another user in the channel. And though minor racist or otherwise abusive remarks may be accepted as a matter of course on IRC as well as Reddit, don't make it your mission to 'pick on' another user. Excessive racism and bigotry is not tolerated, and punishable by a ban.
Tag links that are NSFW as [NSFW] - not every one wants to view mature content. Many are chatting from households, work offices, or just flat out don't want to see that kind of stuff. Failure to do so will result in a warning and an eventual ban. Do not publish referral links without asking openly in the channel if people don't mind you doing so. We're not your army, but we also don't mind helping friends in need.
Support your arguments
Arguing with others is fine; it's the way of life. However, if you're going to argue a point to someone, maintain the high ground and be able to support your arguments with facts. As a whole we hate whiny arguments, so if you're going to argue be smart about it and at least give others a reason to side with you.
Don't flood and don't repeat lines
You will be automatically punished (a quiet or a kick) for doing so. If you continue to do it, it will be grounds for a channel ban.
Don't be easily offended
Don't let remarks get to you. If something or someone on IRC is bothering you, discuss it with a channel operator. Keep in mind that if you're offended often in #reddit, then the real world has quite a few surprises for you.