4-104. The corps headquarters assumes a command relationship over units as they complete integration of personnel equipment and unit logistics and the TSC releases units from their staging areas for onward movement and integration. Even as the units complete RSOI, the corps headquarters ensures that unit commanders and key leaders are briefed on the situation and their subsequent missions. Effective RSOI establishes a smooth flow of personnel, equipment, and materiel from ports of debarkation through employment as reassembled, mission capable forces. A deploying unit is most vulnerable between its arrival and operational employment, so operations security (OPSEC), protection, deception, and dispersion are vital planning considerations. If the corps is conducting operations while major subordinate units are still arriving, the corps commander may employ the corps tactical CP as the corps’ interface with the ESC and arriving forces at the port of debarkation and their various staging areas.