The Rules Kate Middleton Has To Follow Prove Princess Life Is Not Easy
The Royal Family Can't Travel On The Same Plane, Boat Or Train

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A Royal family vacation? That calls for lots of planning! Members of the Royal family should not travel together on the same plane, boat or train. They probably have a vacation planner on payroll!
The rule was set in place to prevent potential heirs of the British throne from dying together in the event of an accident. Therefore, it is unlikely that Kate can travel with her husband and father-in-law Prince Charles at the same time.