I know a guy who you'd never guess was disabled, but he's still carrying a load of shrapnel in his lower legs thanks to stepping on a land mine in a rice paddy in 1970. He said when he gets a new X-Ray tech at the VA he has to explain that no, the machine is not broken, it's just the shrapnel.So Terry, the placard is often for caregivers as well as like what travisstorma said, for disabilities that are not always noticeable.