Pretty sure I understood that from the beginning.

I do remember once though arriving for a flight without an ID (it was in my pocket from the flight the night before) and the Delta agent went through what they would consider acceptable. This was before the current much stricter regulations. Anything with a government logo on it would be acceptable if I had anything else with a photo match. Do you have a voter registration card? Library card? Social Security Card? Yes, Yes, and Yes, but I don't carry them day to day.

Car registration? In the car. Get that and something with your picture and you will be OK. So that day I cleared security and flew from New York to Atlanta using a BJ's shopping card, and a registration for a Saab Convertible that was acceptable because it was issued by the State of Connecticut and had my name on it. That was a while ago, and I'm still loyal to that parking lot because I called and asked and they sent the bus driver back with my registration so I didn't have to go to the lot.