The couple have announced that they will be inviting more than 2,000 members of the public into the grounds of Windsor Castle to watch part of their wedding.

Etiquette tips for anyone whether going to a royal wedding, a domestic wedding, or dinner at the boss’s house, said Hanson, include “if you don’t know what to do, just watch what your host or the most learned guest is doing and copy them.

“Even if they are technically getting it wrong, from the purest guest point of view, if they are doing it they will think that it is correct, so you can sort of bluff your way through it by sort of copying them.”

Ouyang Xueyan contributed to this story.