4-49. The receipt of the Military Surface Deployment and Distribution Command port call message and the United States Air Force (USAF) Air Mobility Command air tasking order initiates port of embarkation operations and specifies the dates when units arrive at the port. An air tasking order is a method used to task and disseminate to components, subordinate units, and command and control agencies projected sorties, capabilities and/or forces to targets and specific missions (JP 3-30). At the installation staging areas, units verify movement data, and they inspect equipment to ensure that it is correctly configured for movement by the designated mode of transportation. Unit vehicles and cargo move to the ports of embarkation by convoy or commercial surface transport.