This might help.... written by Don Charlwood, a 103 Sqn navigator who later went into ATC in Australia. It's from one of his many books:
Take-Off to Touchdown: The Story of Air Traffic Control, published in 1967 (my emphasis):
Let us take as an example the well-known RAF aerodrome of Manston. The first returning bomber to call Manston control might be B for Baker. The exchange of requests and instructions would run as follows:
'Hello Bluefrock, this is Baker. Over.'
'Hello Baker, this is Bluefrock. Clear to land runway 18, QFE1002. Over.'
'Hello Bluefrock, this is Baker. Wilco. Out.'
Which meant that B for Baker was to land in the direction of 180 degrees - or to the south - and that the adjustment to the altimeter to ensure that it read the aircraft's correct height above the aerodrome was 1002 millibars. Baker's reply of 'wilco' simply meant 'will comply'.
Below them the crew of -Baker would see a widespread circle of lights surrounding not only the arodrome but extending over a mile from the landing area. In the blacked-out conditions of wartime England this 'outer circle' would show up clearly on all but the worst nights. The pilot would follow this circle round at a thousand feet until he reached the downwind side of the aerodrome. There he would call, 'Downwind', to which the tower would reply, 'Pancake', signifying 'Clear to land'. The pilot would begin descending then from a thousand feet and turn to face the runway in use, guided by a 'funnel' of lights leading to the flarepath itself. Lastly he would watch for a green light from the airfield controller, who was positioned in a van beside the runway and had an uninterrupted view of runway activity.
Adam