After reading all the discussion here, I’d like to come back to this:
Really, doesn’t this cover it, assuming we’re not going to go the detailed-laundry-list route? If this isn’t enough, then at most I think we should do this, but I don’t think we need to.
Whatever we do would be accompanied by public guidance for moderators, which can be updated as needed just like any other help. The code, though – the thing we expect users to explicitly agree to – should be aspirational and durable. We don’t want to be changing our terms/code monthly like some sites. (Facebook used to do that, which was one reason I never signed up.)
@ArtOfCode, this is my proposal (the first quote, from @luap42).