Various sniper variants have been used by the United States Navy SEALs. Often mistaken for the M21 in the overt literature, only one of them has received a standard name in the U.S. military designations system: the M25, developed by the Special Forces. SEALs also use the Mk 14 Mod 0 Enhanced Battle Rifle (EBR) for close-quarters battle and in a designated marksman role. "Delta Force" units are known to have used M14 sniper variants. Eric L. Haney indicated in his memoir "Inside Delta Force" that every soldier going through the Operator Training Course trained on the M14. According to "", the well-known account of the Battle of Mogadishu, Sergeant First Class Randy Shughart used an M14 for sniping from helicopters to provide support fire to ground troops.