Have packs, clubs, troops, camps or whatever as long as it's not a clan, herd or gang.
Have club/pack... descriptions in profiles as long as there is no word saying "clan." If they want to say medicine cat is ___ and a description, or starpaw is the mate to stripedclaw, it's ok.
If they want to list all of the members of the club, troop, pack whatever it is, that's ok.
They may RP Warrior Cats if they wish as long as it's "tweaked" to comply with the no violence, no harassment/bulling of others, no territories.
They may not:
Have clan in the profile, such as Thunderclan or Starclan.
They may not say: area is south part of Horse Isle, or Haven isle... = Territories. They may not claim ponds as theirs, they may not fight, or harass/bully others. They may not use public chat (only chat here, buddy or pm.)
Hope this helps. If you have questions feel free to ask, I will try to answer as quickly as possible