Competing in the cut-throat Internet search sector, and prepping for a possible IPO, Google has good reason to promote itself. Privately, even rivals grudgingly concede it has done a masterful job.

In recent weeks, Google beat out Apple, Coca-Cola and Starbucks for BrandChannel.com's "brand of the year" honor and was featured in a Boston Globe Magazine cover story chronicling the use of the company's technology as a cultural phenomenon (albeit one that raises some privacy questions).

But even as the Mountain View, Calif., company's marketers celebrate its growing clout (or to use the industry's unabashedly Orwellian term, "mindshare"), its intellectual property lawyers are quietly waging a campaign to insure Google doesn't fall victim to its own success.

The effort centers on trademarks -- government protection for words or logos indicating the source or quality of a product or service. For example, Coca-Cola's trademark bars competitors from passing their beverages off as Coke. Soda-lovers know what to expect when they select the red and white logo, be it in Milwaukee or Marrakech.

But trademark law gets murky when a product or service becomes so successful it becomes "generic." When this threshold is crossed, trademark holders effectively surrender their rights. This is Google's concern. It can't afford have its name be synonymous with Internet search -- at least not in a courtroom.

Hence its note to Word Spy, an online dictionary that compiles and defines new words popping up in the media. At issue is this Word Spy entry: "google (GOO.gul) v. To search for information on the Web, particularly by using the Google search engine; to search the Web for information related to a new or potential girlfriend or boyfriend."

Google lawyers sent the site's editor a letter (portions of which were later posted to an online discussion board) saying that it wants "to make sure that when people use 'Google,' they are referring to the services our company provides and not to Internet searching in general."

Lawyers weren't as upset with the definition as they were the lack of mention of the corporate entity. Word Spy's editor modified the entry by inserting a trademark information, which satisfied Google.

Google declined comment on the practice, but confirmed that letters were mailed to Word Spy and others.

Edward Naughton, a intellectual property lawyer with the firm Holland & Knight in Boston, said Google's tack is a heavy-handed tactic but sound corporate law. The fact that Word Spy is a reference site likely factored into Google's action, Naughton added.

Judges in trademark cases use several criteria to determine if a brand has crept into the public domain. These include consulting dictionaries, surveying the term's usage in the media, and the results of consumer surveys.

"This letter was clearly sent by Google to try and convince Word Spy to take the reference out of the dictionary so there wouldn't be the foundation that it was generic," Naughton said.

The tactic then, which doesn't threaten legal action (there don't appear to be grounds for trademark violation or unfair competition suit), could accomplish two goals: eliminating, or recasting, a definition that could come back to haunt it; and making clear to the site's visitors, who could later be potential consumer survey respondents, that Google is a company not a verb.

Rulings, whether they take place in civil court or in the U.S. Patent and Trademark Office, have cut both ways, Naughton said. For example, aspirin, escalator, bundt cake, ice beer, light beer (or, if you prefer Miller and aren't picky about spelling, Lite) have all slipped into the public realm.

In the technology world, United Airlines lost its bid to trademark e-Ticket, and AOL was denied "You've Got Mail." As with most cases, the courts did not grant ownership because the phrases were descriptive of the service.

There have been successful defenses as well, but only by determined companies. Xerox is the most notable. The copier company has gone to great lengths, both through legal means and its own marketing campaigns, to prevent competitors from selling "xerox" or "xeroxing" machines.