The other day I was catching a nearly full flight on which I was listed in coach (Y), but after processing all of the oversales (OS) and upgrades, the only seats remaining were in first class. The agent then cleared all of the standbys into first class. After getting the seat assignment Sabre showed all of the non-revs cleared into the X cabin and I assumed that I wouldn't be charged for clearing into first class since I didn't list for it. I checked today and it turns out I was charged what the normal NRSA charge is for listing in first class on that particular flight. Is this standard procedure for when there is a circumstance with only F cabin seats available? Just curious even though premium upgrade charges are being eliminated in a few days.