Royal rules can be a bit of a mystery, even to people within the family.

EvenKing Charles has broken rules and protocolsover the years.

For instance, even curtsies and bows aren’t mandatory for greeting a monarch.

King Charles and Princess Anne standing together

So how do the royals know when to adhere to convention and when to set a new precedent?

However, the monarch did not have the authority to make her style mandatory.

Other family members have felt free to make their own polish choices.

Meghan Markle smiling and wearing black nail polish

Way back in the ’90s, Princess Diana rocked a bright red polish.

While the kids initially requested a royal autograph, Kate suggested artwork instead.

“I can’t write my name, but I can draw,” she informed them, perHello!

Prince Harry’s signature on a cast

“I’m not allowed to write my signature.

It’s just one of those rules,” she added.

Whileroyal autographs are forbiddendue to forgery concerns, this rule has been broken on a couple of occasions.

Prince William, Kate Middleton and baby Prince George in front of plane

In 2010, King Charles broke this rule when he visited Cornwall after a flood.

Prince Harry also broke the autograph rule in 2010 when he wrote “Get well soon!

Harry” on the cast of a 17-year-old girl.

Kate Middleton hugging a woman

After her broken arm healed, she planned to preserve the royal’s signature in a glass case.

Even so, this convention is not a compulsory policy.

“There is no official rule on this.

Prince William taking selfie with two fans

It is something that the Queen has the final say on,” a royal spokesperson explained toBBCin 2014.

Now that Charles is king, he’s the one who can make decisions on his grandchildren’s travel.

Protocol aside, recent royal appearances have included a marked trend in heartfelt displays of hugging.

“It felt like a son hugging a father, William Burns told theDaily Mail.

“It was a boost.

Prince Harry agreed with his grandmother, telling an Australian fan, perHello!

“Selfies are bad.

Just take a normal photograph!”

Even so, there’s never been an official rule prohibiting royal selfies.

Royal selfies are now more prevalent than ever.

Catherine, Princess of Wales, has long been a natural at participating in this jot down of photo.