Published by the Air Ministry in July 1941. Instructional recognition silhouette or 'spotter' cards in a full set of four packs, each denoted by colour - 'Red Pack' (denoting the card backs as red and depicting silhouettes of single-engined aircraft), 'Blue' pack -silhouettes of multi-engined aircraft (single rudder); 'Orange' pack -silhouettes of multi-engined aircraft (twin rudders) and 'Green' pack -silhouettes of miscellaneous aircraft. Each pack comprises 53 card with four distinct/separate views of each aircraft, plus a joker, and the four views represent 'suits', and are as follows: 'General perspective view'; 'Front view'; 'Plan view'; 'Side view'. The Joker shows three or four views of each aircraft on one card. Comes with a folded 'key' sheet for each pack that shows the cards complete with details for each aircraft. Marked 'For Official Use Only'. The cards cover allied and axis aircraft and are in excellent condition whilst their boxes have age related soiling. The 'key' sheets are complete but a little stained/dog-eared and the main box is worn with repairs and a section of the lid missing. Nevertheless, this is a very good set overall and quite rare to find complete. Note also that different sets were produced in different years throughout the war. Stock code P17682.