The United States Army has used military berets as headgear with various uniforms beginning in World War II. Since June 14, 2001, a black beret is worn by all U.S. Army troops unless the soldier is approved to wear a different distinctive beret. A maroon beret has been adopted as official headdress by the Airborne forces, a tan beret by the 75th Ranger Regiment, a brown beret by the Security Force Assistance Brigades, and a green beret by the Special Forces. In 2011, the Army replaced the black wool beret with the patrol cap as the default headgear for the Army Combat Uniform.