WSOP
That's true, in AuxAF (then RAuxAF) parlance, the squadrons were 'county' squadrons e.g 609 (County of West Riding), 611 (County of West Lancashire), although the system produced some oddities such as 610 (County of Chester).
Possibly even more interesting, and something that is not well known, is that some regular personnel in the 1950s/1960s were recruited from a specific local area that allowed them to serve at the unit and live at home. Not sure why this was done, recruitment difficulties, perhaps?