Royal Ascot, a 300-year-old highlight of Britain's social calendar attended by Queen Elizabeth and other royals, has taken a stand against shrinking skirts and novelty outfits, issuing strict guidelines about what to wear to the five-day event.

In the Grandstand, where tickets start from 43 pounds ($65), the rules stipulate no strapless dresses or bare midriffs for women and no branded clothing or fancy dress while skirts must be a "modest" length and men need a shirt and tie.

Turn left into the exclusive Royal Enclosure and women must wear hats, with headpiece-style fascinators banned, and men have to be attired in top hats, morning dress and black shoes.

Although royal decorum may have been a little more exuberant than usual on Thursday after her majesty's horse Estimate galloped to win the Gold Cup, the first time a horse owned by a reigning monarch has won the showcase event in its 207-year history.

Anyone breaking the rules of dress can expect a tap on the shoulder by one of 20 dress-code assistants standing at the entrance with a not-to-be-refused offer to buy a tie or pashmina for five pounds or rent a hat or waistcoat for a refundable 50 pounds on return of the clothing.

"We are here to help people have a wonderful day," said one of the smiling dress code assistants, dressed in a chic metallic-grey suit and matching hat.

Nick Smith, a spokesman for Royal Ascot, said organizers had previously taken a passive attitude towards fashion but last year decided to set clear guidelines as women in next-to-nothing or men in bacon-and-eggs hats misrepresented Ascot.

As well as being a race meeting it is a social event, founded by Queen Anne in 1711 and attended every year by the Queen who arrives in a horse-drawn carriage at the racecourse in Ascot, 10 km from Windsor Castle.

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On Gold Cup Day on Thursday, known as Ladies' Day, the queen arrived in a lilac outfit, adding to a sea of colour, feathers, and eye-wateringly high shoes brightening a cloudy day.

"It needed to be reiterated that this is a formal event and we are proud of that although that does not mean that it has to be stuffy or old-fashioned," Smith told Reuters.

"There are not many events in society or real life where you have to dress up and people were glad we make the rules clear."

Last year various items of clothing were given free to racegoers who inadvertently broke the dress code but this year is the first time of paying for errors.

"We can't afford to continue to pay for transgressions," said Smith, adding that any profit from the sales would go to charity.

Most racegoers welcomed the rules which were sent out with tickets last year and publicized online.

"We need to bring some class and elegance back into this world where so many girls look trashy," said Mimi Theobald, 28, a milliner from Inverness, Scotland, from under a huge white hat with a tartan bow and black and white feathers.

With the stricter dress rules, Smith said some people did not make the cut and a handful were turned away this year. Most of those refused entry were women whose skirts failed to meet the rule of being of "modest length falling just above the knee".

"It's hard to provide an on-the-spot solution for that so we direct people to (the nearest shops) but we are here to help and our aim is to make sure everyone has a great day," Smith said.

Photos: Reuters

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