The 13 oddest rules the royal family must follow.

That bit about Prince Philip walking behind Queen Elizabeth -- I recall an anecdote ("Reader's Digest", perhaps) concerning that custom.
It seems someone thought he was too close, and reminded him to stay to the rear. Prince Philip replied that it was quite alright where he was, because "We went to a cricket match together yesterday, and now we are quite chummy."

I like the, "They must accept any gift" I think the challenge is on. Any good ideas?