Maybe Zone-7 refers to the old days when city judge, Arthur Kaplan, ran the entire city limits chasing 67 and 4's in a white Ford LTD with a Q siren.
Anybody remember that guy? He used to get into arguements with Grady dispatcher Ruby Porter when they ran on Med-6. She had a speech impediment. He was always in a hurry.
But seriously, years ago didn't APD refer to the airport unit as Zone-7?
A Regency with a handful of crystals was way fun back then.