For various reasons I had to dig very deep to find out what my experience has been. And I can't now be 100% sure that any O clas fare that I have flown on has had this provision, because although I have seen it in the notes in EF fare listings, it does not appear on ITA and the ITA rules are the ones I usually save. But given the number I've done over the years, and the amount of time that this provision has been knocking around, I think that I very probably have done.

What I have been able to check for the last half a dozen years or so is that I have not in that time had an O class ZA domestic that did not earn frequent flyer miles, with BA or QF (to which I have often credited these occasional single sectors if paid in cash).