The SS (Schutzstaffel): Stabsscharführer
Translated as “Staff Squad Leader,” the position of Stabsscharführer was denoted by a special sleeve chevron, worn on the upper right shoulder of the field grey SS uniform. There is ample photographic evidence, however, that the sleeve chevron was often worn on the left sleeve, or not at all.
Those holding the rank of Stabsscharführer had the choice of being address either by their actual rank title (Unterscharführer, Oberscharführer, etc) or simply by the title of Stabsscharführer. The position of Stabsscharführer is most often considered equivalent to a First Sergeant in the militaries of other nations. The position of Stabsscharführer was unique to the Waffen-SS and was not used by branches of the Allgemeine or “General” SS.
Sources: Wikipedia; Picture courtesy of: U.S. National Archives