Hello,

As a Canadian, I have recently found out the amazing deals available from american airlines, and have started to travel to Buffalo to catch flights. We are travelling from Buffalo to Houston on Southwest (round-trip purchased online "internet special") in about a month, and I have come across various topics on this forum referring to "SSSS" and its connection to extra security and/or not being able to check in on-line. Although, we didn't have any difficulties on our last flight from Buffalo, I am curious about what the "SSSS" means and who/what it applies to.

Thanks for your help.