Kate, the Princess of Wales, follows strict curtsying rules.

She must always be courteous to the King and Camilla, Queen Consort when they meet for the first time.

If members of the same rank are styled as His or Her Royal Highness, they do not have to curtsy to each other.

Royals need to show respect to King Charles III or Queen Consort.

The Duke and Duchess of Edinburgh have to curtsy to the King and Queen Consort.

Kate does not have to curtsy again to the King and Queen Consort if their paths have already met that day.

Without her husband, Kate must curtsy to other family members.

Princess Beatrice and Princess Eugenie are "princesses of the blood."

These rules are part of royal etiquette and protocol.