"0030" . . . . "540 Squadron" . . . . . . . . "540" . . "A mosquito" . . . . "No. 540 Squadron" . . . . . "No. 540" . "No. 540 Squadron RAF" . "No. 540 Squadron RAF" . "(The badge indicates the squadron as the first user of the de Havilland Mosquito)" . . . . . . . "and Dec 1947 \u2013 Aug 1953)" . "Latin: Sine qua non" . . "1942" . . "DH (Nov 1945 \u2013 Sep 1946" . "1956" . . "(Translation: \\\"Indispensable\\\")" . "540 Squadron Royal Air Force" . "Photographic reconnaissance" . "0019" .