In January organisers announced a change of dress code.
Spokesman Nick Smith said: "It is stretching a point to say standards have collapsed but there is no doubt that our customers would like to get back to a situation where it is universally acknowledged that this is a formal occasion and not an occasion where you might dress as you would at a nightclub."
Now, Ascot have sent 100,000 style guides to Grandstand ticket holders and those attending the Royal Enclosure with clear guidelines on what to wear. The style guide is the first of its kind.
The Duchess of Cambridge and Princess Eugenie will have to make sure they adhere to the rules, including almost no showing of the knee.
The guide is complete with do's and don'ts, and features outifts that are compliant with the unique dress code.
Rules include straps of at least one inch in width, trouser suits full in length that match, and hats are a must.
Midriffs, fascinators and knees are a no-no.
As for the gentlemen, they are "kindly reminded that it is a requirement to wear either black or grey morning dress which must include: a waistcoat and tie, a black or grey top hat and black shoes. Cravats are out.