what is ssss on boarding pass

The "SSSS" on a boarding pass stands for Secondary Security Screening Selection. It is a tag printed on the boarding pass to indicate that the passenger has been selected for additional security screening processes. These additional screening processes may include a pat-down, swabbing for explosives, and a luggage inspection. The SSSS code is printed on the boarding pass to flag airline passengers for "enhanced" screening, and it overrides pre-approval through a Trusted Traveler Program such as TSA PreCheck. If a passenger sees the SSSS code on their boarding pass, they can expect that their trip through TSA security will take extra time, as they will be walked through additional security screening procedures, perhaps to include a full-body pat-down.