For the empirical proof, look at the filings with the government for new trademarks that, put simply, are brand names.

Applications surged in the dot-com years, peaking in 2000 and then falling sharply for two years, before rising to a record last year of more than 394,000.

Recently, a new front has opened in the Internet branding wars.

It lies beyond putting trademarks on new businesses, Web site addresses and online logos. Now, companies want to slap a brand on still vaguely defined products and services in the uncharted ephemera of cyberspace -- the computing cloud, as it has come to be known.

Cloud computing usually refers to Internet services or software that the user accesses through a Web browser on a personal computer, cell phone or other device. The digital service is delivered remotely, from somewhere off in the computing cloud, in the fashion of Google’s Internet search service.

Dell has tried to trademark the term cloud computing itself. But in August, the U.S. Patent and Trademark Office sent a strong signal that cloud computing cannot be trademarked.

It issued an initial refusal to Dell, which filed its application 18 months ago, when the term was less widely used in industry conversations and marketing.

Dell had passed early steps toward approval, but the office turned it down, after protests from industry experts that cloud computing had become a broadly descriptive term, and not one linked to a single company. Dell can appeal, but that seems unlikely.

In recent years, patents -- not trademarks -- have been the main focus of intellectual property experts and the courts, especially around the issue of whether patents on software and business methods have become counterproductive, inhibiting innovation.

But some legal experts say trademark issues may take on a higher profile, fueled by the escalating value of brands in general and trademark holders increasingly trying to assert their rights, especially on the Internet.

"Trademark is the sleeping giant of intellectual property," said Paul Goldstein, a professor at the Stanford law school.

Microsoft, for example, is developing a technology that is intended to synchronize the data on all of a person’s computing devices, even synchronizing it with family members and work colleagues as well, automatically reaching across the cloud.

When Microsoft announced the concept this year, it said the technology would be called Live Mesh. Just what it is and how it may work remains unclear, but Microsoft filed for a trademark on Live Mesh in June, an application that awaits judgment from the Patent and Trademark Office.

Mesh and mesh networking are widely used terms for technology that connects devices.

"This is the challenge for our examiners," said Lynne Beresford, commissioner for trademarks in the Patent and Trademark Office. "With emerging marks in a field that is changing quickly, you have to make a determination about what the common understanding is."

That challenge, legal experts say, is one of several for trademark policy and practice in the Internet age. Instant communication, aggressive business tactics and an unsettled legal environment, they say, mean that trademark disputes on the Internet will increase in number and intensity. (NYT)