I think I might have an idea of what that sticker is. In IAH
when your bag goes down in the bagroom they put a sticker on your bag to correspond to what pier it goes to. In IAH
they have roughly 20 piers. The bag will go down to the bagroom and the scanners then read that barcode and send it to the correct pier. Also if your a connecting passenger and have a long layover the bag runners will put it on a belt outside and send your bag also to the bagroom. This is just to keep it inside out of the elements. Plus makes it easier on the runner. So is AS
uses that same sort of system that would be my best guess. Hope this helps a little bit.
p.s. This is what CO
uses in IAH
. With the volume of bags it makes it easier to sort bags. It is similar to what FedEx uses to sort their packages, if that clears it up for you.