Withdrawn orders are flagged so they do not ship

An order the customer withdrew from now says so itself. In All orders its row carries a red "Contract withdrawal" badge, and the expanded order opens with a "do not ship this order" box - with the withdrawal's date and number, the refund deadline if it was paid, and a link to the withdrawal. If you still press Register with courier, you are asked first. Register batch skips such orders and says how many and why, and automatic registration never ships them on its own - so you don't pay a label and a return leg for an order the customer no longer wants.