On your pass, you’ll find a six-digit alphanumeric code. This is what you use to pull up your boarding pass online or at the gate.

In the airline industry, it’s known as a PNR — passenger name reference. And it stores information ranging from your seat and full itinerary as well as form of payment. So keep the boarding pass and don’t simply discard it at the end of your flight.

That PNR code could be used to access your information by folks who shouldn’t have it. If you see SSSS on your boarding pass, make sure to budget in extra time at security. This stands for “secondary security screening selection,” and it means that you’ve been pre-chosen for additional screening.

Be aware that historically, this profiling happens more to folks who buy one-way tickets within 24 hours of their flights. I’ve also just described a typical business passenger!