That’s common knowledge, you don’t even know that? What do you mean, “frenchie detected”?!
(Jokes aside, I think that is why, noticing the small text in french at the bottom left of a map, they probably assume you already know cause its targeted toward french people)
Whoever made these maps definitely knew about it lmao
I’m pretty sure that its general knowledge though, I don’t remember if I learned the height in school