19 C.F.R. § 148.114 Shipment of unaccompanied articles.
Title 19 - Customs Duties
One copy of the validated Customs Form 255 shall be returned to the vendor. The vendor shall place the form in an envelope, affix it to the outside of the shipment, and clearly mark the outside of the shipment “Unaccompanied Tourist Shipment.” [T.D. 78–394, 43 FR 49790, Oct. 25, 1978]
Title 19: Customs Duties
PART 148—PERSONAL DECLARATIONS AND EXEMPTIONS
Subpart K—Unaccompanied Shipments From American Samoa, Guam, the Commonwealth of the Northern Mariana Islands, or the Virgin Islands of the United States
§ 148.114 Shipment of unaccompanied articles.

