A one-year volunteer, short EF (de: Einjährig-Freiwilliger[1]), was, in a number of national armed forces, a conscript who agreed to pay his own costs for the procurement of equipment, food and clothing, in return for spending a shorter-than-usual term on active military service and the opportunity for promotion to Reserve Officers.[2]
The "one-year volunteer service" (de: Einjährig-Freiwilligen-Dienst) was first introduced 1814 in Prussia and was inherited by the German Empire from 1871 until 1918. It was also used by the Austro-Hungarian Army, from 1868 until 1918, and the Austro-Hungarian Navy. One-year volunteers also existed in the national armies of Bavaria, France and Russia.