 They are usually career infantry men rising from the ranks of the enlisted infantry MOSs.Sergeant of other Marine MOSs may laterally transfer and be trained as one of the basic 03 Infantry MOSs before promotion to 0369, but they may not laterally move into this MOS as a Staff Non Commissioned Officer.By virtue of their MOS experience, deployments, and longevity, they supervise and coordinate the preparation of personnel, weapons and equipment for movement and combat, the establishment and operation of unit command posts, the fire and movement between tactical units, the fire of supporting arms, and the unit resupply and casualty evacuation effort.