1. When you are with other people, it's like a RPG with turns. Let others react.
2. Put only your intent, not your specific actions, if it includes another player. You can say whatever a NPC does or what happens to him, but not to a player. (One very good example would be fay's first post in the RP, "If Ruui's attack landed, he would be able to break his opponent's focus enough to then proceed to sweep his feet off the ground. Once he landed on ....")
3. If you want to include another player, ask for permission first. You can also create awesome battles by communication, as DR said before, let us talk first here or in a PM.
4. Be a sport and let it be without bias as possible. Take the situation and let it fair for others. If there's something unclear, or a disagreement, then discuss here first and arrive at a conclusion. If both side are still stubborn, then there's the GM to decide the result.
5. Most importantly, make it fun for everybody. (Smoke weed gaishzz...) Only a metaphor or something, don't do it IRL. xD
This is my understanding of the basic rules of RPing according to what I have read, and also the tons of questions I asked DR. By far, I haven't been scolded yetby the GM, so I guess what the rules are right.
So let us follow try and abide by these guidelines to provide less headache for our beloved GM, as maintaining order in a virtual world created by 10 imaginative minds is a very hard thing to do.
P.S. Can the RP veterans expand/edit/add to the above guidelines? I'm only a newbie so I'm very sure that there is something lacking/wrong there.