ALNWICK, England — Has a piece of advice ever seemed so apt, or so frightfully ironic?

Thirteen years ago, Stuart Manley stumbled upon a slightly faded red poster tucked at the bottom of a box of books he had bought at auction. Unfolding it, he found himself staring at a relic of World War II, a long-forgotten piece of government propaganda bearing the logo of the British crown and this pithy message:

Keep calm and carry on.

British war-era poster: In the May 1 Section A, a headline on an article about a British World War II-era poster with the slogan "Keep calm and carry on" in said that there was a copyright dispute over the phrase. The dispute is over a trademark. Also, a photo caption that accompanied the story referred to a vendor's copyright. It should have said trademark. —

Charmed by its classic design and no-fuss stoicism, Manley and his wife, Mary, framed the vintage poster and hung it up by the cash register in their secondhand bookshop in a disused Victorian train station in the far north of England. After many admiring comments and inquiries from customers, Manley started selling copies — behind Mary's back, because she didn't want to commercialize it.

Ahem. Enter perhaps the most commercialized British product since David Beckham.

Manley's little side venture spawned a marketing and cultural phenomenon, inspiring a million imitations around the world ("Keep calm and kill zombies," anyone?) and also, alas, one very acrimonious feud.

The Manleys and other traders are caught in a spat with an enterprising Englishman who, after launching his own line of "Keep calm and carry on" products, trademarked the phrase with European authorities two years ago. A slogan originally intended as a public exhortation to a nation at war is now the intellectual property of one person, who has forced some other vendors to stop using it.

The businessman, a former TV producer named Mark Coop, insists he's simply protecting the interests and brand of the company he has worked hard to build since 2007. His foes accuse him of trying to monopolize a piece of history.

"He's a smart chap," says Stuart Manley. "No ethics, but smart."

The Manleys and their allies are hoping that their legal appeal to overturn the trademark, which gives Coop exclusive rights to "Keep calm and carry on" in all 27 countries of the European Union, will succeed. A decision is expected soon.

Until then, the merchants fighting to free those five little words from private ownership have no choice but to heed them.

"By and large we do," Manley says with a rueful smile.

The Manleys never envisaged that their serendipitous find here in the historic town of Alnwick (pronounced "Ann-ick"), close to the Scottish border, would wind up a cultural touchstone. About the only claim to international fame for Alnwick up to now has been its medieval castle, which provided a backdrop for broom-flying youngsters in the first Harry Potter movie.

What seemed to the Manleys as just a bit of quintessential British nostalgia has morphed into an international industry.

Visitors to an aviary featuring birds of prey in southern England can buy mugs proclaiming "Keep calm and carrion." For aspiring Jedi knights, T-shirts advise "Calm you shall keep and carry on you must," with an outline of Yoda's head in place of the British crown. lists nearly 100,000 products with "Keep calm" in their descriptions.

Almost all use a version of the no-frills, slightly fusty font that lends the original poster its retro feel. Coop's trademark does not give him control over the visual factor or all the many parodies.

The Manleys say they are sick of the endless iterations, especially Mary, who had objected to selling copies of the poster in the first place, for fear of sullying the purity of it.