Originally Posted by
carnarvon
O is the fare bucket INTO which you will go if you either buy a classic business class ticket with miles or upgrade from Eco/premoium eco TO business class with miles.
C is a paid full flex business class fare; paid with either money of miles (I did not know C was for Flex Award, but if you say so, I assume it to be right)
AFAIK, there are no upgrade vouchers with AF/KLM.
Z is discounted business class fare (leasure). Never heard of this fare bucket applying to awards.
Actually I met many Z class award ticket.(tips to check which class you are requesting from fb award ticket, just log in mobile airfrance website.)
Originally Z applies for paid ticket, but yes, FB rolls out many award ticket with paid ticket class for skyrocketing miles.
And I guess DL learns a lot from FB regarding it.