I would like to add a rule like:
-Do not write the following types of posts "My character thinks xxx about yyy" or "My character's character is like xxx" and of the like.
Why?
I think the main issue is IC/OOC separation. I often see people say "I think xxx about yyy is wrong", and then you don't know it's their character thinking, them thinking zzz would have been a better choice then xxx given what their character knows, or them thinking xxx is OOC-ly wrong. That leads to problems and aggressiveness in the long run.
When the separation is made clear, then it's ok. I think the forum is the perfect place to say things like "I never understood why Kepler Keplerson torched this city in last year's war - it clearly cost them as they could have taken it over instead", "My character Kepler Keplerson was not so much interested in new lands but mostly to punish the City Lord for an insult he made to him a few months before".
