administrative and exercise appointments. Administrative appointment-holders' shoulderboards have additional loops and whorls known as "fishes" in addition to their existing one, two or three stripes. Exercise appointment-holders wear yellow rank insignia appropriate to the appointment of the officer cadet. For example, an exercise platoon commander will wear two bars of a lieutenant, and his exercise platoon sergeant will wear a brassard with first sergeant's chevrons. United Kingdom In the United Kingdom, the rank of officer cadet is held by trainee officers in the Royal Military Academy Sandhurst, at Britannia Royal Naval College in Dartmouth, and the Royal Air Force College at RAF Cranwell, as well as students who are part of the Defence Technical Undergraduate Scheme (DTUS). They are referred to and addressed as, for example, "Mr Smith" or "Miss Smith", or more formally as "Officer Cadet Smith". As they do not hold the King's commission, they are not saluted. It is also used by members of University Royal Naval Units, University Officer Training Corps, and University Air Squadrons however these are not trainee officers and most do not join the armed forces. Royal Navy In Britannia Royal Naval College, Dartmouth, the rank is non-substantive and only used in the initial phases of training, after which officers use their substantive rank of Midshipman. Formerly, cadets at the Royal Naval College, Osborne, and Dartmouth, had the substantive rank of "naval cadet", or "cadet, RN" until passing out of Dartmouth as a midshipman. Royal Navy officer cadets wear shoulder flashes with a white square after they complete the Militarisation phase of training (15 weeks). Formerly, the insignia was a navy blue patch on both sides of the coat collar, with a white buttonhole and gold button, similar to a midshipman's patch. They continue to wear these tabs until they pass out of BRNC at the end of their initial training. The No.1 uniform bears the rank the cadet will hold upon completing initial officer training. Royal Marines In the Royal Marines, the rank is held by those undergoing the Young Officer Training Course, the 15-month training course which is undertaken in various stages at the Commando Training Centre Royal Marines, Britannia Royal Naval College and in the United States. Army The rank of officer cadet is held by those undergoing either the Regular Commissioning Course at Sandhurst or the Army Reserve Commissioning Course holding an AOSB main board pass. The Army Reserve