The problem is anyone can read any post. So, even though a comment was meant for one particular string, many people can carry it into other threads. It's literally impossible to avoid triggering everyone. Also, the boards aren't dialogues. It's not like you are having a one on one conversation with someone. It's a free for all. Everyone's talking and responding to everyone. Someone may start a string but it quickly takes on a life of its own. It's hard to post anything and trigger no one.

I guess some basic rules would be don't be graphic and don't be overtly hostile to anyone. Frustration happens, but hostility should be flagged as should graphic descriptions of triggerable events.