Looking for some clarification on upgrade codes KLM
 

I've been searching for a bit, but I can't find a clear answer to some of these codes referring to upgrades at AF/KLM

Business - Classic Award & Upgrade (O) - This one seems pretty clear to me. Seat available for upgrade with miles. (which I've never been able to get any availability of on any trans-continental flight over the past 12 months :confused: )

Business - Flex Award for Elites (C) - I have no idea what this is. I'm guessing that Plat members (I'm gold myself) can apply for this award? But is it an award ticket or a miles upgrade?

Business - Upgrade with DL SWU/Global Upgrades & Fare Class (Z) - This is the one where you can upgrade with vouchers from AF/KLM or their partners I think?

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.

That's better than not having any option to redeem miles ;)

Yes, but it will add many complexity when you check "real" award ticket.

elites can also upgrade into Z but only from Y. But seeing as I have never had a long-haul Y ticket (even after selecting full flexibility always end up B or M), I've never seen this in practice. But every time I call to upgrade, if O is unavailable I'm asked if I'd like to pay up to Y at which point I could use miles to book into Z. Never obliged. Would probably be cheaper to just pay up to Z.

It's not the "codes" that appears to be the problem. You appear to be totally unfamiliar with Flying Blue.

Perhaps you should start here:

https://www.flyingblue.com/award-tickets.html

You can use a (Delta) GUC (Global Upgrade Certificate) when there is Z inventory.