Those lucky enough to meet a member of the Royal family must remember a short but important list of traditions.
It’s “your Majesty”, upon first meeting the Queen, and “ma’am”, pronounced like “palm”, thereafter. “Your Royal highness” will do for lesser ranks. Men, it is said, should bow at first sight, while women curtsy.
And, as etiquette experts Debrett’s advise, the latter “should be a discreet but dignified movement, with a slow rise, maintaining eye contact”.
Yet, despite this guidance, the greeting can also be an opportunity to add a little flourish of one’s own, as Prime Minister Theresa May has proved.
Here she is on Wednesday, shaking hands with Prince William in France to mark the centenary of the Battle of Amiens.
And it’s not the first time the PM, nicknamed the ‘Maybot’ by her cruellest critics, has made an awkward lunge when a nod would probably suffice.