What Does ‘SSSS’ on Your Boarding Pass Mean? (And How to Stay Calm When You See It)

You’ve checked in.
Printed your boarding pass.
Grabbed your coffee.
And then you see it—right there at the bottom of the barcode:
SSSS
Four little letters that feel like a punch to the gut.
No warning.
No explanation.
Just… extra screening.
Suddenly, your stress level skyrockets.