Originally Posted by ElmhurstNick
I had it a couple of weeks ago ORD-OAK. It's essentially a non-refundable, capacity controlled, walk-up ticket. And because it's not Y/B, it doesn't qualify for various things, including greater corporate discounts, free upgrades for 1Ks, etc.
It also DOES qualify for a few important things. Since it is U, it qualifies for econo plus if you are not elligible. Not bad for a refundable walkup, 1 way, econo plus fare.