I admit it. I am a Final Fantasy junkie. Yes, I did go to see Dear Friends in concert when it was traveling. Yes I did play Final Fantasy XI for several years. I was Tovaud on Phoenix. I played with several Japanese players. Players from a culture that commanded the utmost respect between people. I have a few things that will quickly earn a place on my ignore list, mainly because doing these things got you ignored in FFXI.
1. Never send another player an invite to a group or warband without first sending a /tell or otherwise communicating with him or her first. This is considered rude because a player could in communication to join another group when the invite is sent. This will cause the player to mistakenly join the wrong group and thereby waste several people's time because he will then have to leave your group and request another invite from the correct party.
In WAR, I extend this to do not join an open party without having some kind of communication going on first. The party or warband could be looking for a a specific person or class and you will make it difficult for that person to join the proper group if you are not in communication beforehand. Obviously, if you see something in /t4 saying the effect of "Hey, join my warband! All welcome!" that would be considered the proper communication. Just don't join a random group before some kind of communication has taken place.
2. If you are going to leave a group, be afk or otherwise not be actively playing, please inform the group ahead of time. This avoids the whole everyone taking a scenario and wondering where the second healer/tank/dps is. I have a VERY low tolerance for this. I understand sometimes having emergencies come up. That's fine on occasion. But if you aren't able to actively play in the group, please say so and leave so the group can get someone else. Yeah, it's your 15 bucks. But it's their 75 bucks, or their 345 bucks if talking about a warband.
3. One person leads. Everyone else follows. There should not be conflicting orders given in the party or warband. The word of the party or warband leader is final. If you don't like it, keep it to yourself and bring it up afterwards, or leave. Even you think the leader is wrong, you do what he or she says out of respect for the leader.
4. Assume everyone knows what they are doing. This does apply to following the leader of a group or warband, but I separated this more for leaders of groups. I know what a lot of you are thinking, especially those in Strength in Numbers on Volkmar. What the crap is this guy doing lecturing on respect? Has he listened to himself leading a warband on vent? Follow me for a second here. I presume the all players in my group are capable of playing at the highest level of performance. I presume, even if it not correct, that you can play with the best. This is why you hear Dekar, Gov and me being tough when leading and things are not going correctly. We all assume upfront, that we have A team players in our group. So we treat you like you are A team players. If we were to go easy when there is bad play, we would appear that we accept it as the best you have. It's not respectful to you to treat you like a lower class player by accepting it. If we can make you believe you are a top tier player, you are 90% of the way to being one. Don't worry about winning or losing. If you follow instructions and you lose, that's the leader's fault and the leader should take responsibility should a loss occur when instructions were followed.
5. Set expectations upfront. If you only have a limited time to play, let the group know upfront. Obviously this goes for leading as well. Let the group know how you do things upfront if the group does not already know.
These 5 things go a long way towards building goodwill towards other players.