815 ILCS 393/5
As used in this Act:
"Bona fide purchaser" means a person who in good faith makes a purchase without notice of any outstanding rights of others.
"Plastic bulk merchandise container" means a plastic crate, pallet, or shell used by a product producer, distributor, or retailer for the bulk transportation or storage of goods for sale at retail, including, but not limited to, containers of milk, eggs, or bottled beverage products. For purposes of this definition, a plastic pallet means a plastic portable platform upon which containers, product, or material is placed to facilitate handling.
"Proof of ownership" includes a bill of sale or other evidence showing that an item has been sold to the person possessing the item for fair market value and that the person possessing the item is a bona fide purchaser of the item.
815 ILCS 393/5