Permission for transhipment requires sealing cargo with a customs one-time-lock, subject to exemption based on goods or transport. Permission for transhipment requires that, once goods are loaded on the conveyance under approval, the proper officer ensure the cargo is sealed securely with a customs one-time-lock; an exemption permits movement without the one-time-lock depending on the nature of goods or manner of transport; the proper officer must endorse the Customs Transit Declaration with the one-time-lock number when used.