Recent discussions on issues like TOU and evangelical Christian posts makes me think of this ..

The TOU don't cover everything and can be ambiguously interpreted. Moderators who arbitrarily enforce unclear TOU and unclear rules can become the victim of vitriolic attack.

To overcome this, what is to stop a moderator running a thread within a tribe where "rules" and perhaps "purpose" are discussed and agreed upon?

This would empower moderators with terms of reference when addressing issues during conflict and problem times.. TOU are all very well - but democratically establishing some rules to cricket seems a great idea. (Especially when a tribe's subject is a contentious issue(s) likely to see open conflict)... I have seen such things assist moderators resolve conflict and address the behaviour of rogue members in the past..

I have only done that in one tribe I moderate. That is a tribe where people discuss stuff which is very personal and confidential. The rules are designed to protect that confidentiality, make people comfortable with posting information, and also establishing rules on who, and how, members are admitted... We have nine agreed rules (sorry but I cant post them here..) and these were established within the first few weeks of the tribes existence.. People who want to become members must be supplied the rules and agree to them prior to joining this private tribe..

Have other mods posted threads where rules of conduct and content are discussed and agreed upon ?