When did the term "Storm troopers" first develop? How this carried over to the "Brown Shirts" in 1920s?

One of the major developments of the First World War was the storm trooper. These were ault troops trained in squads as trench fighters and formed by individual regiments from 1915 with the Sturm-Bataillone being developed in late 1915 early 1916. Each of these Sturm-Bataillone consisted of 2-4 companies with a machine gun, flame-thrower and mortar or Minenwerfer companies. This raised the old and still on going argument against elite formations , that is that by concentrating the best men in these companies the quality of the normal infantry decreased, this led to most of these storm battalions being broken up. It is important not to confuse these troops with the shock divisions used in 1917-18 who were chosen to make counter attacks rather than defend like ordinary divisions.