People are just realising what four digit 'kiss of death' code means on boarding pass

A four-digit boarding pass code has been deemed the "kiss of death" after news spread on about its meaning. Reports emerged that the US Transportation Security Administration (TSA) puts the code on the boarding passes of passengers who need to be inspected by security personnel.

The four-digit 'SSSS' code, which stands for secondary security screening selection, is a implemented by the TSA following the 9/11 attacks. Speaking to Fox News, senior aviation writer for The Point Guys, Zach Griff, revealed that it was "implemented by security authorities in the US to screen certain passengers with additional checks". Extra screening processes can include inspection of carry-on luggage, personal questioning, enhanced pat-downs and electronic device screening.

The TSA hasn't publicly revealed the criteria for SSSS selection, but there were a number of factors said to influence it.

Those who are on watchlists, purchase tickets with cash or frequently fly to destinations deemed 'high-risk' by are thought to be at higher risk of enhanced security checks.

Additionally, passengers who booked could be subject to the checks.

On Reddit, some social media users called it the "kiss of death", while one impacted flyer said they had more than 22 hours of travel ahead, adding "I already know that SSSS designation is going to make this hell."

One passenger shared their experience: "Happened to me this year. Extra screening in Venice and then just as my spouse passed the ticket scanner and was heading down the ramp, I was right behind him and got pulled out. At the gate! Again.

"He wondered where the hell I went. Everyone else is boarding. I'm in a little room off to the side. More searches. More questions.

"I was one of the last to board. I was worried I wouldn't have a spot for my carry-on (I only do carry-on) and didn't want to have to check it. My spouse made sure a spot was saved."

Another downplayed it, saying: "It happens to all who travel frequently. You are simply going to be subjected to a more thorough security screening. It's annoying but no big deal."