Don't be a jerk
Don't be a jerk.<ref name="def">The term "jerk" in this essay is generally defined as "an abrasive and inconsiderate person" of either gender.</ref> If people abided by this, we wouldn't need any other policies about behaviour.
"Don't be a jerk" is the fundamental rule of all total social spaces. Every other policy for getting along is a special case of it. It is, of course, a bad idea to be one. So don't do it.
No definition of being a jerk has been provided. This is deliberate. If a significant number of reasonable people suggest, whether bluntly or politely, that you are being a jerk, the odds are good that you are not entirely in the right.
Being right about an issue does not mean you're not being a jerk! jerks can be right — but they're still jerks; if there's something in what they say that is worth hearing, it goes unheard, because no one likes listening to jerks. It doesn't matter how right they are.
Being a jerk isn't equivalent to being uncivil or impolite (though uncivil and impolite jerks are not unheard of.) One can be perfectly civil and follow every rule of etiquette and still be a jerk. The use of a vulgar term to convey the concept is intentional and serves to distinguish this principle from issues of politeness and other protocols of interaction. To avoid being a jerk is not a matter of obeying etiquette but is a broader and more important concern.
Coping with being labeled a jerk
If you've been labeled as a jerk, especially if you have been told this by several people in a particular community, it might be wise to consider the possibility that it is true. If you suspect that you may be a jerk, the first step is to become aware of it. Ask yourself what behavior might be causing this perception, and if you can't work it out, politely ask those that perceive it to explain or clarify. Once you have determined which behaviors are causing the problem, try changing them and your mode of presentation. In particular, identify the harsh words in your communications and replace them with softer ones.
Honestly examine your motivations. Are you here to contribute to discussion and let others have a good time? Or is your goal really to find fault, get your views across, or be the one in control? Perhaps secretly inside you even enjoy the thrill of a little confrontation. This may not make you a bad person, but to everyone who is trying to enjoy themselves, you become an impediment. People get frustrated, rancor ensues, the atmosphere changes, and the whole project suffers. Are you here to give, or to take?
If appropriate, publicly apologize to anyone to whom you may have been a jerk. It's okay; this won't make you seem weak. On the contrary, people will take notice of your willingness to cooperate and will almost always meet your efforts with increased respect.
How to deal with jerks without being a jerk yourself
Telling someone “Don't be a jerk” is usually a jerk-move — especially if it’s true. It upsets the other person and it reduces the chance that they’ll listen to what you say.
Focus on behaviour, not on the individual. Be specific about what you want. Be specific about why you want it. Be specific about why the other person’s behaviour is counter-productive. If you don’t understand why someone is doing something, ask.
Above all, be genuine. Don’t ask questions when you know the answer. Don’t say you want one thing if you want another. Don’t try to persuade people of things that aren’t true. Never respond to a jerk by becoming a jerk.