Why would you be forced to use an ASCOT C/S when that specifically referred to an AT&AAR task (deriving, as it does, from: Air Support Command Operational Tasking)
Now that was my regular argument with Stn Ops at Waddo, but more often we were told to use ASCOT and not RAFAIR. You could still file RFR and call yourself ‘RAFAIR’ until the Turkey/Iraq boarder where the Dip Clearance had been filed for ‘RRR’. We would then briefly become ‘ASCOT’ to get through, before promptly returning to RAFAIR over Kuwait.
I never did manage to find where the confusion arose, and with over half of Sqn being ex-route queens, there was little incentive from them to get RAFAIR to become the norm!