Cam
My knowledge of the second great set-to is limited so I can't see we'll need to take this off topic because of anything I know
As far as I can work out, RCAF squadron numbers were changed (into the 400-series) only when/if transferred into RAF command.
According to Halley "RAAF squadrons were often found in RAF commands alongside similarly-numbered South African and Indian Air Force units. RNZAF squadrons operating in the South Pacific were seldon in contact with RAF units, all those operating in Europe and Africa being numbered in the 400-series. No 1 Squadron, Southern Rhodesian Air Force, became No 237 Squadron to avoid confusion with No 1 Squadron SAAF, also flying in East Africa."
It's rather like trying to sort out the history of RNAS units.
Graeme
PS (required WW1 reference) - I prefer using n Sqn AFC, so I'm with you on that one.