For those who aren’t frequent flyers, navigating the airport and boarding a flight can be a stressful experience. From dealing with potential delays in getting to the airport to long security lines and the unpredictability of flight cancellations, what should be a straightforward and exciting journey can quickly turn into a headache.

Add to that the uncertainty of what might appear on your boarding pass, and it can feel like even more of a challenge.

We can all agree that strict airport security is a good thing in today’s world. I, for one, don’t mind the occasional extra check or a longer wait in line if it means ensuring that nothing dangerous makes it onto a commercial flight. However, I can understand the frustration of being randomly selected for extra security measures. For many, it can feel like an annoying inconvenience, especially when they have nothing to hide.

That’s why, the next time you fly from or to the United States, you might want to take a close look at your boarding pass. Some tickets will feature an “SSSS” code, signaling that you’ve been chosen for additional security checks.

It’s important to note that seeing this code doesn’t mean you’ve done anything wrong. It simply means that you’ve been “randomly selected” for a more thorough security screening.

In 2024, travel influencer Jordyn Verzera shared a TikTok video that shed light on what this code means. Her partner, fellow content creator JT Mocarski, discovered the “SSSS” code on his boarding pass and detailed the extra security he underwent.

Verzera’s caption explained, “On flights to/from the US, you can get ‘randomly’ selected to undergo a much higher level of security. For my partner, this meant separating all of his things from mine, pulling absolutely everything out of his bag, swabbing everything, and making sure his laptop turned on (so they could inspect it).”

So, what exactly does “SSSS” mean? It stands for “Secondary Security Screening Selection.” Travelers with this designation can expect a more detailed inspection by the Transportation Security Administration (TSA). This could involve anything from having their bags completely searched to having their personal items swabbed and even having their electronics inspected in greater detail.

In the comment section of the TikTok video, other travelers shared their own experiences with the dreaded “SSSS” code. One user recalled: “This happened to me the last time I flew out to see my best friend. The TSA scanned my phone and made a copy of all my texts, app messages, pictures, etc. The whole thing was weird and violating, but I guess the TSA can enjoy all the close-up shots of weird pimples I can’t regularly see, lol.”

Another commenter, who had served in the military for 20 years, shared their surprise: “I never understood this algorithm. I got ‘SSSS’ and I’m a Veteran and a 20-year federal employee.”

A third traveler added: “I was flagged all the time because I used to fly solo before I turned 18.”

While the reasons behind the “SSSS” flagging can be unclear, it’s clear that it affects a wide range of passengers. Whether you’re a frequent flyer, a first-time traveler, or someone who may have had an unusual travel history, there’s no rhyme or reason to who gets randomly selected.