Royal Family rule Kate Middleton always follows - but Prince William broke on one occasion

Kate signs a visitors book on a visit to St David's last September
William once broke this royal rule -Credit:PA

When out on official engagements, the royals are bound by a myriad of strict protocols.

Long-standing speculation has questioned whether they can engage in everyday gestures like hugging, taking selfies, or if royal women can sport coloured nail polish. It seems there's an unwritten rule for nearly every situation.

Yet, one peculiar protocol was verified by the Princess of Wales herself, and while she appears to comply, Prince William has notably deviated from it.

The unexpected regulation emerged when Kate attended the Chelsea Flower Show last year. In conversation with some curious youngsters, she disclosed that there's one thing she cannot give as a keepsake, even though it's a fairly straightforward ask.

As Kate mingled with the children at the Royal Entomological Society's garden, identifying bugs and creating drawings, the kids sought a lasting memento and asked her to autograph their artwork, reports the Mirror.

But as reported by The Telegraph, she explained: "My name's Catherine. I'm not allowed to write my signature, it's just one of those rules."

Instead of leaving them disappointed, she contributed sketches including a flower, a tree, and a pond framed by plants.

Earlier this month, however, William acknowledged he had flouted this obscure royal edict during his visit to an iconic beach in Cornwall.

Whilst visiting Fistral Beach, a chap made a nine-year-old lad's day. Young Phoenix Kanes bravely approached the prince, requesting an autograph on the plaster cast protecting his broken arm - and he graciously acquiesced, with a playful caution: "Shhh, don't tell anyone. I'm not meant to do that! ".

However, there appears to be a royal rule that has been conveniently disregarded since the passing of the late Queen; rejecting selfie requests. Instead, it seems that this is now wholeheartedly embraced, with numerous well-wishers brandishing their mobiles at royal events in expectation - evident by sightings of William and Kate cheerfully arm-in-arm with the public for photo ops.

Though not an official part of protocol, several royals had previously voiced their displeasure with selfies. In 2018, Prince William self-proclaimed himself to be 'allergic' to selfies, while his younger sibling Prince Harry made it known in 2015 that he detested them, urging a fan in Australia to opt for a standard photo instead.

He told her: "No, I hate selfies. Seriously, you need to get out of it (the habit), I know you're young, selfies are bad. Just take a normal photograph!".

Even the late Queen had a reported distaste for selfies, with Meghan Markle once informing fans during her inaugural royal engagement in Nottingham in 2017: "We're not allowed to do selfies."

However, it seems there are no such regulations concerning selfies anymore.

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