S/SU/AC means Systems/ Systems Upgrades and Advanced Concepts in
Military
Similar to S/SU/AC
6-DOF - Six Degree Of Freedom
60SSC - 60th Signal Service Company
615 AMOG - 615th Air Mobility Operations Group
63B - Light Wheeled Vehicle Mechanic
63Y - Track Vehicle Mechanic Mos
643ASG - 643rd Area Support Group
645TD - 645th Tank Destroyer Battalion
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