One of the exception codes we are supposed to be getting (but aren't) is:
AA - Car not loaded or empty
While we do deal with partial loads, as far as our system is concerned, a non-empty car is a load. There is no provision for loadish or emptyish. I think this must be the code for Schrödinger's car. Until you weigh it, or open the hatch to inspect it, the car is neither loaded nor empty. If we lose it between scanners as we are wont to do, that muddies things even more.
"Where's my shipment of subatomic particle board?"
"Well sir, that car, which is potentially neither loaded nor empty, may or may not be in any of the following locations..."