Ah, that makes sense, though I can't think of that many constructions where that rule works: "Un curieux animal" and "un animal curieux" mean different things ("a curious-looking animal" and "an animal that seems to feel curious"), and I think that's a one-off rule more than an instance of a general rule.

I suspect some adjectives "naturally" go in front of the noun (those Alicorn listed), but you can put them behind it for extra emphasis; the rest always go behind. With a lot of idiomatic exceptions like "curieux" which means something different depending on whether it's before or after the noun.