Master Gunnery Sgt. Kelvin Jackson, National Training Team chief, Marine Corps Recruiting Command, teaches professional selling skills to marketing public affairs representatives in Stafford, Va., Sept. 9. The fifteen MPARs attended a two week course that taught skills to be more effective with execute their duties. - Master Gunnery Sgt. Kelvin Jackson, National Training Team chief, Marine Corps Recruiting Command, teaches professional selling skills to marketing public affairs representatives in Stafford, Va., Sept. 9. The fifteen MPARs attended a two week course that taught skills to be more effective with execute their duties.