It was while I was putting the finishing touches to The Independent Book of the Royal Wedding that it occurred to me that one thing matters above all else when writing about the Royal Family: taste. Tempting as it is to relate every detail of the royal fairytale (a priceless story involving Wills and Kate and a troupe of Ibizan ladyboys at La Maison de Bang Bang, for example), it would be inappropriate – perhaps even tacky.

The question of taste is never mentioned in royal circles; it is simply there. There are occasional lapses – it is said that Prince Andrew once wore a Playboy Club tie at a Palace garden party. They are noted, then politely forgotten. All the same, there were fears that the Middleton family might pose problems of basic decorum for the Royal Family. When Kate's father, "Mike", first met the Queen, he was wearing brown suede shoes with a dark suit. "Her Majesty was appalled but said nothing," a royal aide tells me. "She simply had a word with an equerry. It won't happen again."

The decision to allow 100 members of the public to attend the wedding has raised more questions of etiquette, and a committee of royal insiders experienced in dealing with ordinary people – among them, Prince William's private secretary, James Lowther-Pinkerton, ex-royal nanny Tiggy Legge-Bourke, and family friend Isabella Anstruther-Gough-Calthorpe – has been set up.

Although the committee has been asked to be broad-minded when considering applicants, there are to be ground rules. As a committee member confided, "It's not snobbery but common sense to ensure there are no tattoos in the Abbey, or chewing-gum, or obesity, or 'kids' fiddling with computer games."

Another ticklish problem of taste surrounds the role of Kate's high-living uncle Gary Goldsmith. It is said that Goldsmith, who will be the first Gary to become a member of the Royal Family, has never quite been forgiven for putting on a vaudeville act known as Los Raunchy LadyBoys di San Antonio while the royal couple were staying at his Ibizan villa, La Maison de Bang Bang.

"Wills and Kate smiled through the thing until the finale, which involved ping pong balls," a Maison de Bang Bang regular tells me.

When it comes to decorum, it seems, the Royal Family has nothing to fear from courteous Kate Middleton.