Prince Harry and Meghan Markle are expected to push the Royal protocol boundaries at their wedding on Saturday.
He's sixth in line to the throne.
Etiquette coach William Hanson told Mike Hosking although he matters as a person, Prince Harry doesn't matter in the scheme of the hereditary monarchy.
He says he and Meghan Markle can do things differently.
"Everything from, well now supposedly having Meghan's mother, although this hasn't been confirmed, walk her down the aisle to having a gospel choir perform at St George's chapel."
Hanson says they can get away with it, but Prince William and Kate Middleton wouldn't have been able to.
LISTEN ABOVE AS WILLIAM HANSON TALKS TO MIKE HOSKING