If you have preprinted QSL cards that have your home address and grid square on them, what's considered the most proper way to do a physical QSL exchange for a contact that was made while you were operating away from home?
Do you cross out the location info on the QSL card and write in where you actually were? Do you put your operating location on the comment line and hope they notice that and don't bounce your QSL for "not in log"? Do you leave a comment and attach a note to make it really clear you weren't operating from home?