She may well be the wife of Britain's future king but Kate Middleton must toe the royal line and bend the knee for her family.
An updated Order of Precedence, outlined in British newspaper The Sunday Telegraph, directs the 30-year-old Duchess of Cambridge to curtsy when greeting other royals, more so when she is without her husband Prince William.
The new rules of court dictate that the duchess must make the traditional dip to Princess Anne, princesses Beatrice and Eugenie, and the Queen's cousin Princess Alexandra. However when William is present the act is not necessary.
At all times Catherine must curtsy to the Queen, Prince Philip, Prince Charles and his wife Camilla.
The Windsor pecking order dictates that William's aunt, Prince Edward's wife Sophie, must curtsy to Catherine at all times.
News of the revised rules comes after five days of Royal Ascot racing where well-dressed women were seen to offer a range of curtsy styles to Her Majesty.
"Although the etiquette may seem antiquated, it is taken very seriously by the royal family, whose members bow and curtsy to each other," Telegraph reporter Richard Eden wrote.