19 CFR § 11.6 - Distilled spirits, wines, and malt liquors in bulk.
(a) The port director, in his discretion, may require marks, brands, stamps, labels, or similar devices to be placed on any bulk container used for holding, storing, transferring, or conveying imported distilled spirits, wines, and malt liquors, in accordance with 19 U.S.C. 467.
(b) Marks, brands, stamps, labels, or similar devices required by Federal, State, or local statute or regulation may be affixed, and Customs inspection, gauging, marking, or measurement may be done, at the place of unlading or other suitable place, unless the port director determines that inspection, gauging, marking, or measurement shall be done at a public store, warehouse, or other appropriate facility.
(c) Marks, brands, stamps, labels, or similar devices shall be permanent in nature and not subject to obliteration or removal as a result of handling or other condtions. The port director shall determine whether a mark, brand, stamp, label, or similar device is acceptable, based on the nature, surface, and composition of the container.