In the 1960's My lords Commissioners of the Admiralty were meeting regularly in London and elsewhere, concerned that newly lower deck promoted officers, looking young and superior , might be confused with with The Public School Dartmouth Intakes. Conceivably, they might not have a regional accent and pass for Upper Class.( My own father was such an animal) Their Lordships fretted and fulminated , arranging further extensive meetings. For them this was a monumental crisis. But they solved it. The lower deck promoted officers would have SD (Special Duties) embossed on the brass buttons of their reefer jackets. Sorted. The Dartmouth boys would know just who they were standing alongside and looking down on, However:- The Daily Mirror of the day thought this move elitist (never?) and took those pompous admirals to task. The idea was promptly dropped and several admirals floated into oblivion on enhanced pensions. Do you have further salacious details of this dreadful episode of naval history?