Kate Middleton, Princess Charlotte, Prince William
Kate Middleton needs to keep her chin up when descending from a plane. Pictured: Middleton, Princess Charlotte, Prince William board a seaplane before departing Victoria Harbour seaplane terminal in Victoria during the Royal Tour of Canada on October 1, 2016 in Victoria, Canada. Getty Images/Andrew Milligan-WPA Pool

Kate Middleton must follow a rule when departing a plane, but Prince William isn’t expected to do the same thing.

Kara Godfrey, a journalist for Express, claimed that the Duchess of Cambridge needs to keep her chin level to the stairs as she departs the plane. Doing so means that Middleton has good posture, and she’s also engaged with what is front of her.

While holding her chin up, Middleton is also allowed to hold the rail when descending from the plane. However, it is also important to note that there should be a fine balance between keeping the chin so high or too low. The former suggests hastiness, while the latter suggests disinterest.

Myka Meier, an etiquette expert, told The Sun, “One should keep their back straight, chin parallel to the floor, and square the shoulders.”

But things may change a bit when Middleton is carrying her kids because when she is, her head is usually bowed down as she gives them any form of reassurance.

Meanwhile, men are also subjected to a similar rule, but it has been common practice for royals to walk ahead of their wives. Prince William is often ahead of Middleton to make sure that he’s accessible in case she trips. The Duke of Cambridge also walks in front of his wife because he needs to greet foreign dignitaries on the tarmac.

According to Meier, Prince William always extends a hand backward to Middleton while walking out of the plane.

In related news, Prince Harry also walks a few steps ahead of Meghan Markle when getting off the plane. This practice will be seen when the royal couple steps out on their overseas tour of Australia, New Zealand, Fiji, and the Kingdom of Tonga from Oct. 16 to 31.

However, when it comes to Queen Elizabeth II and Prince Philip, Her Majesty always walks ahead of her husband because she is the monarch. Prince Philip walks a few steps behind her.