Kate Middleton and Meghan Markle both break this ridiculous royal rule.

The Duchess of Sussex is popular in ignoring the royals’ fashion rules. In fact, Markle was seen wearing black outfits and pants. She also refused to wear nude tights in the beginning. However, there’s a particular protocol that both Middleton and Markle don’t follow because it’s absurd.

According to InStyle, Middleton is a big violator when it comes to royal blings. According to royal etiquette expert Myka Meier, diamonds are not worn during the day. Before 6 p.m. the only recommended jewelry are metallics, gemstones, pearls and sapphires. Diamonds are only worn at night. However, the Duchess of Cambridge doesn’t follow this. Middleton has been seen wearing diamonds during daylight.

Markle is good at following this, but there are times when she tends to forget it. The Duchess of Sussex was seen wearing diamonds but mostly in the afternoon. She was also photographed with a diamond bracelet from her baptism.

The two duchesses have different tastes when it comes to jewelry. Middleton has been seen wearing several pieces from the Queen’s collection. On the other hand, Markle hasn’t loaned an item from the monarch’s vault except for the tiara on her big day. The reason behind this boils down to their personal preferences.

“Kate is more traditional, classic and refined, whereas I feel Meghan is a little more unexpected and youthful with her choices,” jeweler Pippa Small told People.

Lauren Teff, a London-based stylist also observed the differences in Middleton and Markle’s jewelry choices. According to her, Markle tends to keep her jewelry simple but stylish and contemporary. She also added that the Duchess of Sussex supports smaller designers who make ethical impacts.

On the other hand, Middleton prefers classical brands. "For Kate's style she keeps it simple but tends to go a bit more classic with her [jewelry], think diamond earrings and pearl necklaces," Teff said.

Middleton and Markle are reportedly having a feud. The two duchesses have a ghastly row that began last year when Prince William and Middleton invited Prince Harry and Markle to their home in Norfolk. This year, the Duke and Duchess of Sussex rejected the invitation.