Despite the fact Kate Middleton may one day become queen, she recently learned she must bow down (or in this case, curtsey) to "blood princesses" when she's not in Prince William's company. According to the new Windsor protocol, this includes Kate curtseying to the Princess Royal, Princess Alexandra, and the daughters of the Duke of York, Princesses Beatrice and Eugenie.

Kate does not need to bend the knee to Beatrice and Eugenie when she is with William, however. But confusingly enough, she still must curtsey to the Prince of Wales, the Duchess of Cornwall, the Queen and the Duke of Edinburgh, The Telegraph reports.

The Queen recently circulated around the royal household an updated copy of the Order of Precedence, which is an official paper listing, in descending order, the rankings of the different members in the Royal family.

The document clarified Kate's status: As a former commoner, she must show reverence by curtseying to royal-borns in public and private when her husband, Prince William, is not present. The Countess of Wessex, the wife of Prince Edward, must in turn curtsey to Kate.

According to The Daily Beast, Kate was last seen publicly performing the curtsey two weekends ago when she greeted Prince Philip on the balcony of Buckingham Palace after the Trooping of the Colour ceremony.

The Order was last updated in 2005 after Prince Charles's second marriage.