27 CFR 31.47: Warehouse receipts covering spirits.

The sale of warehouse receipts for distilled spirits is equivalent to the sale of distilled spirits. Accordingly, every person who sells, or offers for sale, warehouse receipts for distilled spirits held or stored in a distilled spirits plant, customs bonded warehouse, or elsewhere, is required to register and keep records as a wholesale dealer in liquors, or as a retail dealer in liquors, as the case may be, at the place where those warehouse receipts are sold, or offered for sale, unless the person is exempt from those requirements under subpart D of this part.