SJSHARKEY:
The example that you show does not mean there are 19 seats in F/C. Actually F is a subset of A. It means that while there are "x" seats avaialble ing F/C (Ths is the "A" part) only the number listed under F is availabele for upgrades, AT THAT TIME. While I am not 100 % sure, I seem to remember travelling on a reward ticket in KLM business class a few years back and it was "D" class. I suspect that the "D" class seats in your example are also a subset of "A". I would like someone to confirm and also tell me what "Z" class is. I think it is the number of seats available for upgrade in true business class.