They may be de facto rules if you get banned or chastised for breaking them.

Yeah, but nobody's getting BANNED for using capital letters to express verbal emphasis in text. It's just a little annoying, and comes across too strong.

So some of them are guidelines, others are rules, but which is which is not for us to know. This is obviously very healthy and constructive :)

I have never read them but I don't have run-ins with moderation because anything an emotionally healthy person would do is legal on HN.

It's emotionally healthy to tell people they're being ridiculous. Can't do that on HN!