Originally Posted by MSPeconomist

DL = Delta, SC = SkyClub, the Delta airport lounges.

When you SDC = Same Day Confirmed, your ticket must be reissued. It would probably take an agent doing some sort of waiver on the computer system for you to avoid the $50 fee. If you have no FF status on DL, they will not allow you to decide to go standby. Technically, you will not go standby: for $50, they will change your ticket within three hours if a seat is available on the desired flight and at that point you will be CONFIRMED on the flight, not just standby. I would be very surprised if you can do this without the fee, lounge or not, unless there is some problem such as your original flight being very late or cancelled.