1.) Never ever trust anyone outside the group.
2.) No accepting of TPA OUTSIDE the GROUP.
3.) Don't let other members do all the work. Everyone must cooperate.
4.) Do your best in everything. This includes everything, from accepting a tpa of your group member fast to save his/her life, to hunting and scavenging of good items for the welfare of the group.
5.) No stealing, no griefing of other members in the group.
6.) And many more that noble ideals.