You know what they say about assumptions. Same thing many say about of $mi/J.

My question is what is it supposed to post as for any buy up? Original fare class, Y, F, A? Something else?

And I could be wrong (happened once before), but I don't see the script on the above link. I did find the updated script on the old page here though.

Such a huge help, so thanks for creating that and this page. I am still confused and will reread this 8 more times and then another 8 before I book anything hoping for an upgrade. (And then try to explain to my mother how she can book a ticket and me upgrade her.)