I dunno. It's difficult, at best, to set up such guidelines. It requires either a didactic attitude or a degree of prescience that few of us are lucky enough to possess. It's easy to say, for instance,
no politics or
no religion, but what seems political to others may not seem political to me. Religion is even worse, since that can vary within particular religious groups, much less from culture to culture. At best,
be polite might be specified, but other folk have a different idea of what
polite might be than my interpretation. Maybe
don't be confrontational? But that would pretty much ban significant areas of discussion. Other than very broad/general suggestions - which I thimk exist, at least in the general
Living Room, Basement and like designations, hard and fast rules tend to limit conversation and chase folk away.
Just my opinion, of course. I've been castigated (to my mind, at least at the time) a time or three, but I'm still here because this forum is one (1) of the very few that allows expression of differences without personal bias or discrimination.