I was called up for NS in Nov '49 and allocated a number 3124*** which I was told indicated I had been in the ATC. As I had volunteered for NS pilot training before actually going to Padgate I must have mentioned the ATC thing at the recruiting office in Ealing. As far as I know nobody had actually confirmed my ATC service. Others had numbers starting 4******. After two years I became Plt Off Bloggs RAFVR with the same number. After a few months I rejoined on a short service commission, retraining the same number. In 1956 I was granted a permanent commission and the number stayed with me until I retired in 1969. In 1976 I joined the RAFVR(T) and still kept that number until they kicked me out kicking and screaming in Dec 1996. Incidentally when I joined BEA my staff number ended in ***75 which I was told indicated a pilot. Don't know if BOAC had a similar system.