This is the TSA we're talking about. The 'code' is probably the words, "Cleared for Precheck" printed on the boarding pass.

I'm sure terrorists will never ever ever figure out how to use Firebug or the built-in Firefox Inspector to edit page text before printing their boarding pass. This hack was featured somewhere, but I lost the link.

I've gone through PreCheck at ATL. Nothing on my BP said PreCheck. Part of the qualifications that the article didn't mention is that certain high level elites are eligible, so it might be whatever designator determines that status.

The TSA agent scanned the BP, there was a beep sequence similar to when you have exit row and they directed me to the other line.

heh, most airports i fly locally the guy scans nothing.

all he has is a ultraviolet(?) lantern and latex gloves.

or some kind of uneditable NFC. they say "embedded" and not printed.

BP don't have NFC, Precheck works for a BP printed at home or at the airport.

My base airport in the US is Atlanta and I have always used the Delta iPhone app which uses a 2D square barcode for a boarding pass.

I had an international flight a few weeks ago and used a paper ticket. For the first time they scanned the paper ticket in the same way as the 2D barcode from the app.

I suspect the "embedded code" is in this 2D barcode and hence why not all airports can "support" this system. They have to have the scanners installed, which most airports don't.

i'd give it a 70/30 odd that the code is shown as a upgrade to "1st class" as i doubt airlines will even bother to save you time if you are flying couch