though a short tour assignment need not be unaccompanied. Historically, most Short Tour Service Ribbons were awarded for service in South Korea, by far the most common short tour assignment in the USAF. From June 2003 until April 2011, Airmen serving in hostile environments for 181 days or more qualified for the Short Tour Service Ribbon under a temporary exception to rules outlined in AFI 36–2110. However, this exemption was rescinded by General Norton A. Schwartz in April 2011 and Airmen will no longer qualify for the award if they arrive in a hostile environment on or after 1 July 2011. The Air and Space Overseas Long Tour Service Ribbon is issued for completion of a standard overseas service assignment of two years or more in length with additional awards denoted by oak leaf clusters. Long tour credit is awarded for completion of an overseas long tour (2 years) prescribed by Department of the Air Force Instructions, or to any member assigned to a United States or overseas location who is subsequently sent under temporary duty orders (to include combat tours) for 365 or more days within a 3-year time frame. Additional awards of the Air and Space Overseas Service Ribbon are denoted by oak leaf clusters and Department of the Air Force regulations permit the receipt and wear of both the short and long tour ribbons simultaneously, wherein the short tour ribbon takes a higher precedence by being worn to the wearer's right of the long tour ribbon. The "A" device is authorized only on the short tour ribbon to any service member who performs a tour of duty at an arctic based Air Force or Space Force facility; most commonly Thule Air Base in Greenland. Coast Guard The Coast Guard Overseas Service Ribbon was approved on 28 October 2009 with details announced on 29 April 2010. It is awarded to active duty members on a permanent assignment and who successfully complete a tour of duty of at least 12 months at an overseas shore-based duty station or on board a cutter permanently assigned to an overseas area. It is also awarded to reservists who are permanently assigned and have satisfactorily completed a minimum of 36 cumulative days of service at an overseas duty station during each 12-month period of the total tour of duty. Duty on board U.S.-based deploying ships or units does not qualify. Personnel who are