The Importer under ISF is generally defined as the party causing goods to arrive within the limits of a port in the U.S. by vessel, but the regulations limits the definition to certain named parties for foreign cargo remaining on board, immediate exportation and transportation and exportation in-bond shipments, and for merchandise being entered into a foreign trade zone.  The limited named parties though per Customs do not take into account commercial reality and designate the Importer as a party that has no commercial interest in the shipment.  Full notice, including proposed definition is available at: https://www.federalregister.gov/articles/2016/07/06/2016-15687/definition-of-importer-security-filing-importer