The Duke and Duchess of Cambridge hired one of the best nannies in the world to help with their three children Prince George, Princess Charlotte and Prince Louis.
Maria Borrallo, who trained at the prestigious Norland College, in Bath, was hired by Prince William and Kate Middleton back in 2014 when George was just eight months old.
She has lived in Kensington Palace ever since and travels with the family on visits and royal tours as a discrete presence.
But as part of the training given at her college, there is one word Maria is banned from saying whenever she's at work.
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On top of learning skills like self-defence and defensive driving, nannies are also reportedly taught not to say a particular word in front of children, according to author Louise Heren who spent a year at the college researching a documentary.
Speaking to The Mirror, she revealed that the women at Norland are taught never to say - Kids.
Instead, George, Charlotte and Louis should always be referred to as children or by their names.
Louise said: "The word kid is banned. It's a mark of respect for the children as individuals."
Maria is also believed to be very strict with the royal children and like all Norland Nannies has a "no-nonsense" approach.
Louise told the Sun : "There will be no messing. That's because Maria will be aware that as they step off planes, holding mum's hands, smiling and waving to the crowds, there can't be any crying or terrible twos or tantrums."
The children have a 7pm bedtime, which has to be stuck to, and all playtime must take place outside, no matter the weather.
Louise said: "Lots of bike rides, playing with their dogs, potentially some gardening. Norland are very into teaching children through play.
"If it is tipping down, they will still go out. Wet weather is just inappropriate clothing, you have to put the right stuff on."
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