I had never heard it before, but at the Atlanta airport the row that they have the cars for the Chairman is called the Red Carpet (RC) isle.

It is the closest isle to where you show up, which is usually where the President and Chairman cars are. I have just never heard to it being referred that way.

Regarding access, there really isn't anything to access. We don't get to pick any car in that isle, it is just where they have our reserved car parked.