Problem is, that it is really a supply register. When I looked in the attic, I could clearly see that the duct supplying it came directly from the plenum (just above the evaporator) that feeds the other ducts to the rest of the house.
I removed the register and found that someone had taped its openings shut, so air couldn't flow either way through it. I sent photos to the inspector of the register showing how it was taped shut. I also taped a small piece of facial tissue to the ceiling and turned on the a/c. It fluttered in the incoming airstream, and was not sucked upwards as it would be if this were a return.
I wanted to just return the taped-shut housing the way it was. But the inspector is being hard-assed. He doesn't want to see anything - supply or return - in the ceiling. I do NOT think he's looking for me to slip him a few bucks.