Yeah I wondered about that, and guessed wrong. I'm used to seeing the words "idling" or "stopping" for cars and "loitering" for people, and never "standing".

I suppose if you want to put non-parking rules (e.g. idling rules) on a parking sign, and then complain that the parking sign is too complicated, then that's a different problem.

I don't think he missed that, I think he used the wrong word to refer to non-commercial vehicles.