Travelers using the program or parole must complete a Form I-736 (online as of February 2018[49][50]), possess a machine-readable passport and non-refundable return ticket, and not travel to the state. Due to specific visa categories for foreign workers from the Northern Marianas, travel between Guam and the Northern Marianas still requires full immigration control and all visitors leaving Guam or the Northern Marianas are inspected, regardless of the final destination. [51] The D visa is issued to crew members of seagoing vessels and international airlines in the United States. These include pilots and cabin crews of commercial companies, captain, engineer or deck of a seaship, service personnel on board a cruise ship and trainees on board a training ship.