What the “SSSS” Code on a Boarding Pass Indicates and Why Travelers Sometimes See It

or regions considered higher risk. Paying cash for airfare may also increase the chance of being flagged. A traveler with little or no established travel history may sometimes be selected as well. At the same time, the system also includes a random element. This unpredictability is intentional, since it helps prevent anyone from learning how to avoid the screening process.

The secondary screening itself is more detailed than normal security. Once at the checkpoint, the traveler is usually directed to a separate lane or screening area. Officers may inspect carry-on luggage item by item, swab bags and electronics for explosive