If a leisurely afternoon in Royal Ascot's Royal Enclosure is on your summer schedule, be prepared to spiff up your wardrobe.
For women, the new rules require hats — not those flirty fascinators — and skirts or dresses of "modest length," the BBC reported.
Men will have to button up in a vest and tie, and no ascots allowed.
Organizers said the dandification of the dress code was an attempt to restore formality at the annual weeklong June horse racing event.
In the less formal grandstand, which is open to the public, the rules are relaxed only slightly, the BBC said.
Women must wear a hat or fascinator, those crosses between a mini-hat and feathery hairband, and strapless or sheer-strap tops and dresses will be banned.
For men, a suit and tie will be mandatory.
"There is no doubt our customers would like to get back to a situation where it is universally acknowledged this is a formal occasion and not an occasion where you might dress as you would at a nightclub," said Ascot spokesman Nick Smith.
