Ranks of the Royal Australian Air Force
The rank structure of the Royal Australian Air Force (RAAF) has been inherited from the Royal Air Force (RAF). The RAF based its officer ranks on the Royal Navy, and its airmen ranks on the British Army. Unlike the RAF, RAAF rank abbreviations are always written in uppercase without spaces (e.g. Pilot Officer is written as PLTOFF, not Plt Off). Also, the RAAF does not have the ranks of Senior Aircraftman, Junior Technician, Chief Technician or Master Aircrew. The rank insignia is very similar to that of the RAF, with the exception of  Leading Aircraftman (LAC)/Leading Aircraftwoman (LACW) which is one chevron (two-bladed propeller in RAF). Both officers and airmen wear rank insignia on the chest when wearing General Purpose Uniform or Disruptive Pattern Combat Uniform. Rank insignia is worn on the shoulder in all other orders of dress with the exception of the Service Dress tunic where it is worn on the lower sleeve for officers and Warrant Officers and the upper sleeve for airmen and the working uniform of Physical Training Instructors where it is worn on the sleeve. The word 'Australia' appears immediately below all rank insignia worn on  the shoulder or chest. The most senior active rank of the RAAF, Air Marshal a three-star rank, is held by the Chief of Air Force. On the occasions that the Chief of the Defence Force is an officer of the RAAF, the rank of Air Chief Marshal is awarded. The rank of Marshal of the Royal Australian Air Force has never been held as an active rank and it was held as an honorary rank by Prince Philip, Duke of Edinburgh until his death in 2021.