Is there anywhere to add rules for tribe use by the community we have somewhere?

There are couple of ways to do that.

1. Add the rules the input box by going to Admin Panel > Content Types and choosing the advanced setting in each content type.
2. If you use groups, write the rules on group description.
3. Creating a post and pinning it to the top of the feed.
4. Create a page on your website and add the link to Navbar or Footer under Admin Panel > Theme.