I would change this to:- for a World Championship Grand Prix (I say Grand Prix as opposed to just race to exclude Indianapolis - Indy definitely doesn't count in my view)
-for an officially sanctioned event for cars complying to contemporary F1 rules.
Neatly rules out Indy and the F2 years, but included non-championship or national championship appearances. I’d consider drivers who took part in the British F1 championship to be F1 drivers for example. But not those taking part in BOSS or FIA historics, even if they’re driving cars that were built to F1 rules.