Going boldly where no lawyers have gone before, the U.S. Patent and Trademark Office yesterday granted the first trademark to a scent.

Clarke's Oh-Sew-Easy Needles of Goleta, Calif., won the historic registration for its line of embroidery threads perfumed with a "high impact fresh floral fragrance reminiscent of plumeria blossoms," erasing 50 years of patent and trademark practice and raising the possibility that companies may soon sue each other not just over products that look alike or feel alike but also smell alike.

"If it looks like a trademark and quacks like a trademark, it is a trademark," said J. David Sams, chairman of the office's Trademark Trial and Appeal Board, explaining the decision.

Yesterday's announcement follows a general trend in federal policy toward allowing companies to file for legal protection for virtually anything associated with their products that they can prove is distinctive and helps to evoke consumer recognition.

In additon to company names like "Xerox" or slogans like "Tastes Great, Less Filling," trademark protection covers things like the shape of the original Coca-Cola bottle, the sound of the old NBC chime and the pink color of Owens-Corning insulation.

But few intellectual property lawyers ever thought to ask for a trademark on something as amorphous as a smell, and those who did never imagined that such an application would be approved by the trademark board.

Even the proprietors of the Clarke company, a six-person, mail-order punch embroidery needle outfit outside of Santa Barbara, admitted to being shocked at the ruling.

"We did this as a kind of gimmick," said Celia Clarke, the company owner. "I never really thought we could do it."

Clarke said that her firm is now considering using its new found legal rights on an entirely new line of products, "perhaps a blanket or an afghan or maybe slippers. . . . We may start saying it's Oh Sew Easy to smell good."

But many trademark lawyers said yesterday that they had no idea whether the ruling will stand up to subsequent legal challenge or how a firm could ever define its rights to a smell, let alone protect that right in a lawsuit against a competitor.

"I have to say that in my mind this raises all kinds of questions," said Marie Driscoll, a New York trademark attorney.

"I frankly can't imagine a judge having sniff tests in the courtroom."

The essence of trademark law is that anything that assists a consumer to distinguish one company's product from another company's is eligible for trademark protection.

Once a firm has that protection, it can sue anyone else who develops a competing product, package or marketing device that is so similar that it might mislead consumers.

A company that called its photocopies "Xerex," for example, would be an immediate target for a trademark infringement suit from the Xerox Co.

But trademark law cannot be used to protect the more general characteristics that a class of products may share.

For many lawyers, that's what smell was.

"The general belief is that no one person should have the right to sell a floral scent or a primarily rose-scented perfume," said Driscoll. "That would restrict competition too much." As a result, most perfume companies protect themselves with trademarks on their packaging and brand name.

But in reviewing the Oh-Sew-Easy application, the trademark board found that no one else was using "high impact . . . plumeria blossoms" fragance -- or any fragrance at all -- in marketing sewing thread.

That made the use of a fragrance distinctive.

In addition, the board found that the California firm had been using the scent so consistently that consumers had come to identify plumeria -- a tropical scrub with deep funnel-shaped, heavily perfumed flowers -- with the company and might reasonably be expected to be confused if a competitor started using it on its thread.

The patent board explicitly stated that it was ruling narrowly on perfumed thread and not on the use of scents in cases where smell is the primary characteristic of a product, like perfumes.

But agency officials said that they expected the decision to be used as the basis for future, broader trademark claims. Oh-Sew-Easy's lawyer said he thought that given the status and commerical significance of many odors, there was no reason trademark law could not be extended in the future to any distinctive smell.

"If I gave you a cotton ball with a fragrance on it, and it was Bazooka bubble gum or Johnson's baby oil or Old Spice, there would be no question in your mind where it came from," said James Hawes, an intellectual property lawyer in Newport Beach, Calif. "Fragrances can be trademarks as well as anything else."

"What this shows is that there is really no legal limit to the types of things which a business through its creativity and inventiveness can develop as identifying itself," said Jerry Gilson, a Chicago trademark attorney. "It goes very far."

Too far?

"I wouldn't say that," Gilson said. "I'm a trademark lawyer."