Originally Posted by
baliktad
Yes, TSO's routinely tell people to do whatever they want.
But more importantly, the response of the barcode reader is still fully in control of the TSA. Right now everyone assumes that a 3 on the barcode means LLL, 3 beeps, and expedited screening 100% of the time. This is an assumption made without a full understanding of the system. The barcode reader can still beep once even when a 3 is present in the barcode.
Exactly. For a data point I checked the last 3 of my US Airways boarding passes that allowed for precheck and there was no 3 in there.