KEY POINTS:
Shoulder straps no thinner than an inch, no bare midriffs or mismatching trouser-suits and a decree from on-high that all women should cover their heads by wearing a "substantial fascinator [an ornate lace or feathered head covering]". Or a hat.
That is not the latest sartorial decree from the Taleban, but an attempt by the authorities at Royal Ascot to bring back what many say is some much-needed class to one of the racing world's most iconic and fashionable dates.
Over the past few years, many of Royal Ascot's more traditional patrons have complained about what they believe are the slipping standards in the Royal Enclosure, where racegoers are expected to dress the part.
Ascot, the mutterers said, is failing to separate the sartorial wheat from the chaff. The traditionalists are not happy.
The governing board has decided upon a new set of guidelines that they hope will make it easier for racegoers to work out what not to wear and will help avoid any embarrassing entry refusals.
The clearer instructions will be sent out to the 80,000 enclosure badge-holders later this month by the Duke of Devonshire. They are more thorough than previous years where "formal daywear with a hat" was the simple but often confusing code for the uninitiated.
This year, badge-holders will be reminded that off-the-shoulder, halter-neck and spaghetti-strapped dresses where the strap is "less than one inch wide" will not be deemed acceptable. The ultimate Ascot faux pas, the miniskirt, is now officially deemed "unsuitable".
"What we are trying to do is make it much clearer to badge-holders what constitutes respectable daywear," said an Ascot spokesman, Nick Smith.
Mr Smith said those who wanted to dress casually for race meetings were still welcome to use the Silver Ring, a separate admission area that does not provide access to the parade ring or the main grandstand.
The former racing broadcaster Peter O'Sullevan welcomed any move that would ensure people continue to dress smartly for Ascot.
"It would be a pity if it became too casual," he said. "I'm not much of a fan of the exhibitionists. I suppose they have their place but we shouldn't all try and emulate them.
"My advice is that if you feel like you're dressed like an exhibitionist you probably are and maybe you should modify your attire."
Jo Bryant, an etiquette adviser at Debrett's, said: "If Ascot has felt the need to issue new guidelines on acceptable dress for the Royal Enclosure, then it is a sign that standards have indeed been slipping."
- INDEPENDENT