A NCO is Non Commissioned Officer they would be your Corporals, Sergeants and Sergeant Majors. A Corrporals uniform would be the same listed on the equipment of a soldier one addition they would be wearing is a white Epaulette would be on the right shoulder. A Sergeant would be verry simmular to a Corporal except instead of one Epaulette they would have two as well a red sash as well the bayonet belt would have a second slot for a short sword. The shoulder arms for a sergeant would be at the advance arms. Sergeant Major would be the same thing as a Sergeant but the role would on the Regiment level the Sergeant would be the one who would form the Regiment on Parade and other regiment level NCO duties asked by the regimental Command.