As far as I am aware there is no requirement to carry anything other than ones personal ID (passport/national ID card) and a licence to operate as a crew member on the aircraft.
In Nice recently my colleague produced his FAA licence upon request and the security muppet looked at both sides of it and asked him which of the two photos (Orville and Wilbur) was him!
It's all a game - treat it as one and enjoy life.