Originally Posted by SEA1K4EVR

Those are probably "buddy passes"... a limited number are given to airline employees. They can be given to friends/family of the employee and those friends/family do not have to be traveling with the employee to use them. They are indeed standby/space available only and they are the lowest possible boarding priority falling below employees traveling themselves on standby. The good thing about them is that if first/business class is available then you can sit there if dressed appropriately.