Originally Posted by jsloan

I do not believe that Y/B/M upgrades are automatic. As I recall, you have to go into the reservation and indicate that you want the instant upgrade. (This may not be necessary when PN > 0). As I recall, it was intended as a way to allow someone to get a Y receipt for expense purposes before claiming the F seat.

I rarely -- if ever -- fly on a Y/B/M fare, but I've seen the "Request an Upgrade" link in my reservation when I've been put into Y during IRROPS.