[rosseloh]

My local airport is so small that they don't process security until half an hour before boarding. We have one "gate", and the planes we get can hold 50 people when full.

I have Precheck (always marked on the boarding pass and I assume it shows up on their screen when I scan it), and what happens is the person at the podium notes it and lets his colleagues down the line know. I get a card, and show it to the person handling the body scanner, at which point they send me through the metal detector instead. There isn't much difference when it comes to the bag scanning (if any).