You are correct as far as fare buckets are concerned, but the anomaly is that there are three fares: Flex+, Flex and Saver. Saver almost seems like a ‘hidden’ fare. For instance when you look at the mileage calculator on the website it is not shown at all, yet (from experience) it earns the same miles as Flex. It books into ‘A’. I don’t know if there are therefore 2 F bucket ‘levels’ or 2 A bucket ‘levels’. All quite strange and unusual: in J and Y there are more buckets than ‘fare types’.