The problem with those rules is that they "all make sense" somewhat (and where details might have been influenced by local idiosyncrasies) locally but if you mix and match them then it gets weird

But the trick here is: if you're relying on the details for your benefit then make 100% sure it's provable (though tbh legal proof is less - and different - than what your HN commenter might understand). Or just make it easy on yourself and don't rely on them