British royal weddings are known for being extravagant celebrations rooted in tradition. Pulling off a royal wedding requires accordance to certain rules and traditions from brides, grooms and guest.

It begins with permission from the reigning monarch to marry and abiding by strict rules about what to wear, the cake you can serve and the flowers in a bride’s bouquet.

Here are 8 rules and traditions for royal weddings.

A look at strict royal rules of etiquette and strange traditions
A look at the royal family’s strict dress code

1. You must receive permission from the monarch to marry

According to the Royal Marriages Act of 1772, no descendants of George II can marry without receiving permission from the reigning monarch, per U.K. Parliament. The act is still in play today and has approved more than 100 marriages since it was passed.

This is not an uncommon practice in the U.S. today. In 2015, The Wall Street Journal reported that 77% of potential suitors still seek a parent’s permission before proposing.

When Prince Harry and Meghan Markle announced their engagement in November 2017, they shared that permission was granted from both Queen Elizabeth and Meghan Markle’s parents.

“His Royal Highness and Ms. Markle became engaged in London earlier this month Prince Harry has informed Her Majesty the Queen and other close members of his family. Prince Harry has also sought and received the blessing of Ms. Markle’s parents,” read the royal family’s statement on Instagram.

2. Brides carry a sprig of myrtle

Queen Victoria started the tradition of carrying myrtle in royal wedding bouquets at her wedding in 1840. Every royal bride since has incorporated myrtle into their wedding bouquet.

“Myrtle, which represents love, fertility and innocence, has been grown at Osborne House, Queen Victoria’s holiday home on the Isle of Wight, for about 170 years,” according to the Royal Family.

The plant still grows on the Osborne land today and is collected for royal weddings.

3. Bouquets go to the Unknown Warrior

Royal brides place their wedding bouquets on the tomb of the Unknown Warrior as they leave Westminster Abbey. The tradition dates back nearly 100 years to Lady Elizabeth Bowes-Lyon’s (also known as the Queen Mother) wedding.

“As Lady Elizabeth entered Westminster Abbey on her wedding day, the Royal bride stopped to lay her flowers at the Tomb of the Unknown Warrior. The gesture was in remembrance of her own brother, Fergus, who died at the Battle of Loos in 1915 and to pay tribute to the millions of others killed and injured in World War I,” according to the Royal Family.

4. Tiaras are for married women

Tiaras are only worn by married women and members of the royal family. Kate never wore a tiara until she married into the royal family. Same for Meghan.

“The old rule is that hats are never worn indoors after 6 p.m., because that is when the ladies changed into evening dress, and tiaras and the family jewels would come out,” etiquette expert Grant Harrold, known as the Royal Butler, told the BBC.

“For married ladies it was a sign of status and would show you were taken and not looking for a husband,” Harrold added. “For the gentleman it was a clear sign not to make advances toward the lady in question.”

5. Fruitcake is the traditional royal wedding cake

Underneath all the elaborate frosted piping of the royal wedding cake lies the humble fruitcake — the kind of dessert expected from a grandmother — but fruitcake once represented wealth and status in Britain.

“A fruitcake was originally a symbol of wealth and prosperity because of its precious ingredients such as dried fruits, alcohol and spices. Furthermore, the cake, in a way, represented the vastness of the British empire, using ingredients from far-flung corners of the globe. A wedding was, and is to this day, a time of celebration, and as such it calls for a cake to match the occasion,” Chris Dodd, pastry chef at London’s Dalloway Terrace, told Vogue.

Many royal weddings serve two cakes, one being the fruitcake. At William and Kate served a eight-tier iced fruitcake as well as an unbaked chocolate biscuit cake, according to Hello Magazine. Harry and Meghan broke tradition and served a lemon and elderflower cake.

6. The bride’s wedding dress must be approved

The reigning monarch must approve of the royal bride’s wedding dress before she walks down the aisle, reports CBS News. Dresses are expected to be either white or cream, feature long sleeves and not show the bride’s shoulders or cleavage.

It was Queen Victoria who sparked the tradition for brides to wear white wedding dresses. At the time, it seemed like an odd choice but it eventually caught on and wearing a white wedding dress became the norm, according to the Victoria & Albert museum.

7. Wedding rings are made from Welsh gold

For more than a century, royals have been using rare gold from a Welsh mine to make their wedding bands.

“The wedding rings of Queen Elizabeth The Queen Mother, Queen Elizabeth, Princess Margaret, Princess Anne, and Diana, Princess of Wales were all made from the same nugget of Welsh gold, which came from a Welsh mine, Clogau St David’s at Bontddu,” according to the Royal Family.

8. Female guest wear hats

One of the most important accessories for a royal wedding is a hat or fascinator (small hat). Female guests are expected to arrive in a hat and classic, modest clothing.

“For a royal wedding, especially in England, it has to be the hat,” Louise Green, a British milliner who has been making hats for 30 years in the U.S., told “Entertainment Tonight.” “Whether you start with the hat and then buy the outfit, or buy the outfit and then buy the hat, you have to have a hat. You can’t go to the royal wedding without a hat.”

“You’re going to see classic clothing,” Green continued. “They’ve already said you have to cover your shoulders. ... There’s not going to be anything provocative in dressing.”

“But then they can go wild with the hat,” she added.