 SSD III concentrates on platoon-level tasks and is required for staff sergeants for them to be eligible for attendance to the Senior Leader Course and consideration for promotion to sergeant first class.SSD IV was developed and launched for Master Sergeants to complete as a prerequisite for attendance to the Sergeants Major Course.SSD V trains promotable master sergeants and sergeants major for nominative and joint assignments and will be a requirement for those positions starting January 1, 2015.