Here's Why Kate Middleton Can Wear a Tiara and Meghan Markle Can't

If you're dying to see Meghan Markle step out in a sparkly tiara, get ready to wait until (at least) May.

Kate Middleton has been known to wear a tiara or two in her time as a royal-by-marriage. She wore Diana's favorite tiara to honor her deceased mother-in-law:

She wore a gorgeous tiara on her wedding day:

Meghan Markle, however, has thus far been tiara-less. Why? Because of royal etiquette, of course.

Why can't Meghan Markle wear a tiara?

The short answer is because she and Harry aren't married yet. According to The Mirror, royal protocol says that unmarried women can't wear tiaras. That means that after her nuptials in May, she will be eligible to wear some very royal jewelry.

When will she wear tiaras once she and Harry tie the knot?

While she could wear a tiara on her wedding day like Kate did, in general, it's an evening-only accessory.

“Flashy diamonds and tiaras are not worn during the day, and only married ladies wear tiaras," etiquette expert Grant Harold told BBC. "For married ladies, it was a sign of status and would show you were taken and not looking for a husband."

But she's not entirely new to wearing crowns.

Recently, photos of Meghan wearing a tiara did surface. It's not a breech of royal protocol though—the pictures are from Meghan's days on the homecoming court.