Seeing “SSSS” on your boarding pass can be alarming, especially if you’ve never encountered it before. But the code does not mean you’re in trouble. SSSS stands for Secondary Security Screening Selection, meaning you’ve been selected for additional security screening before boarding your flight. It’s a security procedure rather than a punishment or accusation.

If you receive SSSS, you may have to undergo additional checks such as a more thorough inspection of your carry-on luggage, a pat-down, swabbing of your hands or belongings, or additional questions about your trip. The process can take extra time, so it’s a good idea to arrive at the airport earlier than usual and allow plenty of time before boarding.

There isn’t always a clear explanation for why someone is selected. It can happen randomly, but factors such as certain travel routes, unusual itineraries, one-way tickets, or similarities between names in security databases may sometimes play a role. Being unable to check in online or being directed to the airport counter can also occur when additional screening is required.

Most importantly, SSSS does not automatically mean you’ve done anything wrong or that you won’t be allowed to fly. In most cases, travelers simply complete the additional screening and continue to their gate. Stay calm, follow the instructions of airport security staff, and give yourself extra time. What looks like a worrying code is usually just another layer of airport security.