Apologies if this is teaching you to suck eggs
Also to do with the role of the Squadron. e.g. 41 Sqn Whilst flying Jaguars as a frontline unit 41(F) (even though the Jag isn't a 'fighter') Now that the FJWOEU (SAOEU in old money) has become 41 Sqn it is 41(R) Sqn. All OCUs (training squadrons) are (R) for reserve.
Nothing wrong with trying to get a bit of tradition, keeping Sqn numbers alive is a good idea in my book.