Hi JohnP
The Canberras of the Strike Squadrons in Germany all retained large underwing serials. However, some sqds had large a/c serials in white on the fus aft of the roundel. 3 Sqd had this scheme as well as individual a/c squadron "fleet" letters on the fin. These identifiers stood out remarkably well against the grey/green camo and black undersides.
I guess the RAF wanted the russkies to know which individual aircraft had delivered instant sunshine to them, in case of any complaints you understand.
