The Ammunition Identification Code (AIC) was a sub-set of the Standard Nomenclature List (SNL). The SNL was an inventory system used from 1930 to 1958 to catalog all the items the Army's Ordnance Corps issued. The AIC was used by the United States Army Ordnance Corps from January, 1942 to 1958. It listed munitions and explosives (items from SNLs P, R, S, and T), items that were considered priority issue for soldiers in combat. The markings used by the system made it easier for soldiers to quickly identify and procure the right items. It used a code that had five parts.