The backside of a credit card, showing the magnetic strip and signature. Color and detail vary across platforms, but often shown as gold, silver, or blue. May be used for banking and other ID cards as well for various content concerning money, including payment. 

Some vendors feature easter eggs: Apple’s design features John Appleseed in the signature and a security code of 448 and Facebook’s design features founder Mark Zuckerberg’s signature and a security code of 123. Samsung’s design previously included the initials KJH.