All referenced bindings should be public

[jariji]

I often seen documentation suggest using some function P.f() which isn't public. I think this is best avoided and could probably be detected by a linter.

[tecosaur]

I think the tough thing here is differentiating between the different ways that private functions are referenced, say "for more information, look at Foo.private" where it's not suggested it be used, or "if you need X, see Foo.private".