While Kate Middleton has been known to break a royal rule here and there, she's a stickler about toeing the line on this one ...

For members of the British royal family, there are many (incredibly strict) style and etiquette rules to follow. Certain colors are off-limits, modesty is always a must, and even something as minor as ...

The rules that govern royal life are well-known and have been passed down through the generations. From heirs not flying together to royals being discouraged from signing autographs, there is no ...

Add Yahoo as a preferred source to see more of our stories on Google. (PA Images via Getty Images) The Duchess of Edinburgh appeared to break an unwritten royal fashion rule on day two of Ascot.