When the Bags module is on, the QR code on a bag label or bag packing slip encodes the link to that bag's page (/bags/<bag number>); scanning it with a phone opens the bag page where staff can see the contents and mark the bag delivered or returned. Without the Bags module the QR code links to the order's details page instead. On the standard Delivery and Pickup labels the QR code always points to the order details page (via a slightly different URL depending on whether the Bags module is on, but it's the order page either way, never a per-bag page). The barcode on all of these encodes the order number padded to 12 digits, so a barcode scanner reads the order ID.