27 CFR §26.312

Distilled spirits brought into the United States from Puerto Rico or the Virgin Islands in containers of 1 gallon (3.785 liters) or less for sale shall be in liquor bottles, including liquor bottles of less than 200 ml capacity, which conform to the applicable standards of fill provided in § 5.47 or § 5.47a of this chapter. Empty liquor bottles, including liquor bottles of less than 200 ml capacity, which conform to the provisions of subpart E of part 5 or part 19 of this chapter, may be brought into the United States for packaging distilled spirits as provided in part 19 of this chapter.