All Royals Must Carry a Black Outfit with Them
This rule is a bit somber, but since the Royals are frequently traveling and photographed regularly, they need to carry a black outfit with them at all times in case someone in the family should die. This way, upon returning to England, they will arrive dressed appropriately. When the Queen’s father died in 1952, she was away in Kenya and did not have appropriate attire. She had to wait on the plane until a black outfit was brought to her, change inside, and then exit.