The term assault weapon is used in the United States to define some types of firearms. The definition varies among regulating jurisdictions but usually includes semi-automatic firearms with a detachable magazine, a pistol grip and sometimes other features such as a vertical forward grip, flash suppressor or barrel shroud. Some firearms are specified by name. At the time that the now-defunct Federal Assault Weapons Ban passed in 1994, the U.S. Department of Justice said, "In general, assault weapons are semiautomatic firearms with a large magazine of ammunition that were designed and configured for rapid fire and combat use." The origin of the term has been attributed to legislators, gun control groups, firearm manufacturers, and the media. It is often used interchangeably with the term "assault rifle", which may more specifically refer to selective-fire military rifles that can fire in automatic or burst mode.