Give residence keys - why bother?

"Oldeseadogge;c-17980377" wrote:
Maybe. Perhaps a monitored attempt in the vanilla version might give a clue. Do your sims that get keys have anything in their inventory or is it something the game is supposed to remember?

I honestly don't know. I never play rotationally, so I haven't played the son since he moved out. I have a feeling it isn't a physical object though, more like some code type thing the game applies to the sim given the key that allows them to bypass the door restrictions and be more like a household member without living there.