Well, the actual keyword is retum. It turns out that most humans can't tell the difference between an r and an n next to each other, or the letter m, so they just decided to go with the quicker to type 'm' instead or 'rn' You've just been reading it wrong.

:D Honestly, I think either ret or return is fine, but I'd match other keywords. So if you're using pub and priv instead of public and private, I'd use ret instead of return as well.

Oh boy I can't count. That criteria is a little tongue-in-cheek. Basically the core developers decided saving those extra three characters wasn't worth it. We implicitly return the last expression, so "return" is typically only used for an early exit. Therefore it's more approachable to new users, and pretty rare so it doesn't add much clutter.

The 'r' is the zeroth character of course.