19 CFR § 10.68 - Procedure.
(a) Theatrical scenery, properties, and effects, motion-picture films (including motion-picture films taken aboard a vessel for exhibition only during an outward voyage and returned for the same purpose during an inward voyage on the same or another vessel), commercial travelers' samples, and professional books, implements, instruments, and tools of trade, occupation, or employment (see § 148.53 of this chapter), of domestic or foreign origin, taken abroad may be returned without formal entry and without payment of duty if an exportation voucher from a carnet, when applicable, or an application on Customs Form 4455, or its electronic equivalent, was filed, and the merchandise was identified as set forth in § 10.8, before exportation of the articles. Articles exported under cover of an A.T.A. carnet (where the carnet serves as the control document) may, in accordance with this paragraph, be returned without entry or the payment of duty. If Customs Form 4455, or its electronic equivalent, is utilized, commercial travelers' samples, professional books, implements, instruments, and tools of trade, occupation, or employment may be returned with either an informal entry or a declaration on Customs Form 3299, or its electronic equivalent; theatrical scenery, properties, and effects and motion-picture films may be returned only with an informal entry. When articles other than those ex ported by mail or parcel post are examined and registered at one port and exported through another port, the port director may require proof of exportation in those cases where the carnet or Customs Form 4455, or its electronic equivalent, does not reflect that these articles were exported under Customs supervision. In the case of commercial travelers' samples taken abroad for temporary use, except where exportation involves certification of a carnet, port directors may waive examination of the samples at the time of exportation. When motion-picture films are to be taken aboard a vessel for exhibition only during an outward voyage and are to be returned for the same purpose during an inward voyage on the same or another vessel, port directors may waive examination and supervision at the time of exportation. When theatrical scenery, properties, and effects are taken abroad in sealed carload lots by rail for temporary use, the cars must be sealed by U.S. Customs officers for entry at any Canadian or Mexican port where U.S. Customs officers are stationed. Application and examination before the time of exportation is waived if a Customs Form 4455, or its electronic equivalent, is filed with the U.S. Customs officer in the appropriate Canadian or Mexican port, and that officer examines the articles before they are released from foreign customs custody by the foreign customs officer.
(b) When any such articles are to be returned to the United States from a contiguous foreign country in which a United States Customs officer is stationed, the articles may be presented to such officer with the duplicate copy of the application for examination and comparison with the descriptive list. Upon completion of such examination, the packages containing the articles shall be corded and sealed or forwarded in cars sealed by Customs officers and shall be manifested in the same manner as personal baggage. Articles so treated shall be released upon arrival in the United States and removal of the seals by Customs officers.
(c) When commercial travelers' samples consisting of raw cotton are taken to and returned from Canada, the application on Customs Form 4455, or its electronic equivalent, shall be executed in triplicate, two copies thereof to be returned to the traveler for surrender to the Customs officer on the return of the samples from Canada.