Strange experience last weekend - first time this has ever happened to me on AA.

As a Gold, I don't expect a lot of upgrades. However, on a very full flight from DFW to MCI, after a long day of meetings, I was thinking a couple cold ones in F sounded nice. Simple sub-500-mile upgrade, figured I had a chance at it.

Sure enough...24 hours prior to departure, my upgrade clears. ^

So I go to check-in...and no F seats are available. My itin shows "upgrade confirmed", seats under airport control. No big deal, I think - I'm not that picky about seat assignment for 1 hour on an MD-80 - I'll just accept whatever seat is available at the gate.

In United-land, this is no problem: you print a boarding pass with no seat assignment, proceed through security, and get your seat at the gate. (I think they call it a "Departure Management" pass.) I've done this several times before...no problems at all with the TSA.

However, I could not find any way to get checked in with AA.com! I called the Gold line; they said try again on the morning of the flight (about 10 hours prior to departure). I did so - no dice. There was no way to check in for the F seat - no equivalent to a "DM" pass.

Fortunately, my exit row seat was still unassigned, so the Gold agent was able to downgrade me. I was then able to print a boarding pass, go to the gate, and add myself to the F upgrade waitlist. I didn't make it and flew the segment in row 21.

Not the end of the world...but I did ask the gate agent if there was anything I could have done, short of showing up very early and physically checking in at the airport. She said I should have been able to print something called an "OS" pass.

Has this happened to others here? What is an OS pass? Is this something I should have known how to print either 24 hours or 10 hours prior to the flight? Wondering...for future reference...since it appears that this may be a somewhat normal occurence for an upgraded Gold (finding F seats under airport control).