For hundreds of years, Debrett's has guided Britain's aristocracy through the niceties of meeting royalty, going to the races or eating soup in the correct way.
Now the publishers of the bible of blue-blooded behavior are straying into previously unmentionable areas of the life of a modern girl -- with a new book offering guidance on adultery, toplessness and celebrity gossip.
The first edition of Debrett's Peerage and Baronetage -- known in Britain as the "toff's bible" was published in 1769, and its tome on manners, Debrett's Correct Form, has guided high society for decades.
But according to its editor, Jo Aitchison, the new book "Etiquette for Girls" is a sign that the traditional arbiters of civility are catching up with the times.
"It's a nod to the modern day," she told Reuters. "We're pulling Debrett's out of Victorian times and trying to make it relevant to today." The book's advice ranges from how to conduct a sleaze-free office fling or a disease-free one night stand, to how to smoke at social occasions and what to do when you meet a celebrity.
"Avoid dark-alley groping and unladylike fumbling in the back of a cab," the guide says on the subject of one night stands. "Discuss the necessaries to avoid planting any love children or disease, and you're away."
On smoking it decrees: "Always use a proper ashtray -- never a wine bottle, flower pot or used plate -- and avoid allowing smoke to billow out of the nostrils. It is also inelegant to leave the cigarette unsupported in the mouth..."
But Aitchison insists the book is not all about sex, lies and partying. The core values of Debrett's remain -- elegance, composure and dignity are all important, whether you are dining with the Queen or cheating on your husband.
"We are trying to give girls confidence to behave in the correct way," she said. "It's a bit like a survival guide for modern life, so we have had to include certain subject matters that are new for Debrett's."
The world of celebrity is "peopled by psycho fans and fame hags," the book says, and is best treated with caution.
As well as advice on affairs, Aitchison points out that the book also includes suggestions on less risqué subjects: How to behave properly on the way to work -- "don't sit on the bus and bellow down your mobile phone" -- and what to take to a music festival -- "earplugs and a pillow."