Someday, when you have a silvery mane, an engorged 401(k), and a 25-year-old mistress on call, you’ll be free to wear French cuffs. You’ll even be entitled to wear them with diamond-encrusted, monogrammed cuff links and blow Cohiba smoke in the faces of the sycophants who work for you. Until then, unless your name is Lagerfeld, Wonka, or Prince Such-and-Such, you do not have license to wear French cuffs—under any circumstances.

“But wait,” Young Finance Guy might protest. “I’m an upwardly mobile stud at a high-profile firm—my superiors all wear bespoke shirts with knuckle-size gold cuff links.” Exactly. Your superiors. An apple-cheeked M.B.A. has as much business dressing like Barry Diller as your grandmother has taking wardrobe cues from Shakira. Instead of giving the impression that the wearer spent his day sealing million-dollar deals, the big-boy cuffs suggest he actually dances jigs for a CEO who’s earned the right to wear his. Ian, a 22-year-old investment banker in New York, wears French cuffs almost all the time, with a rotating collection of cuff links. “We don’t have to dress that way at work,” Ian says. “But I think it makes a good impression.” Plus, come happy hour, the wrist jewelry helps with the ladies: “Cuff links are a conversation piece. If a girl compliments you on them, you get into a whole discussion.”

Once upon a time that rationale might have flown. In Little Women, Jo is so transfixed by the cuff links of her suitor, Mr. Bhaer, that she fumbles her ball of knitting yarn. The French cuff had become voguish in Europe a few years before the publication of Louisa May Alcott’s novel, thanks largely to Alexander Dumas, who debuted his Three Musketeers in fancy sleeves in 1844. It remained a swashbuckler’s affectation for a century, right up to the time of Fiat playboy Gianni Agnelli, who made it part of his signature look. Of course, Agnelli also wore a fat sparkling watch on top of his cuffs, so he’s not exactly a style icon for the Everyman.

“French cuffs are intended to be formal,” says Tom Kalenderian, executive vice president of Barneys New York. “Dressing up a suit is their primary function.”

Or dressing up royals, like Prince William. Wills, in fact, may be part of the inspiration for another breed of French-cuff abusers: the open-cuffers. Witness Jude Law, seen in the limelight more than once with unrestrained shirt cuffs hanging down over his thumbs from beneath the sleeves of an unbuttoned suit jacket. The look: Prince Charming on an early-morning walk of shame.

“This trend is showing up a lot on the red carpet,” Kalenderian says. “The guy who’s doing that is emulating something he’s seen before. It’s not original. You don’t see someone truly stylish doing it.”

Scott Sternberg, founder of preppy-chic men’s label Band of Outsiders, doesn’t condemn shirts with French cuffs altogether, but he thinks they have their place. And that place is in close proximity to a bowl of eggnog.