You can’t call him at Esquire magazine, though. He doesn’t work there and never has, according to the company. Try some of his other 17 e-mail addresses, including "hertz.com" and "trump.com," and you’ll get the same result. He doesn’t work for those companies either, spokesmen said.

But Cashel does own the words they might want to use in their cyberspace addresses.

Cashel — a Kalorama resident who works at the government-funded Eurasia Foundation here — declined to be interviewed for this article. He is among a growing number of people and companies that have registered hundreds of Internet addresses mimicking some of corporate America’s most fiercely guarded trademarks.

Only with an address can a company send and receive e-mail on "the Net." Just as street signs provide directions to buildings, Internet addresses direct information to the right individual. If your name is Mike and you work at XYZ Corp., your Internet address might be mike@xyz.com. Unless, of course, somebody else had already registered @xyz.com. Then you would have to be mike@elsewhere.com.

The unique addresses are handed out on a first-come, first-served basis by an administrative body called InterNIC. Anyone can register any address for free. The only restrictions are Internet naming guidelines, which limit the number of characters and require that a descriptive suffix be included. All business addresses, for instance, must include the suffix ".com," short for "commercial."

The rush by Cashel and others to register potentially valuable names may cost businesses millions. As more companies venture on-line, they may find their name of choice already has been registered by a speculator, a competitor, an employee or even a company in a different industry with a similar name. At stake is corporate identity in the information age.

Companies whose potential names have been registered by others will have three choices: Pick another name, buy the rights to the original one or sue.

"There are big corporate names being registered, and it appears that it is individuals and not companies who are responsible," said Mike Walsh, the president of Internet Info, a Falls Church market research firm that tracks corporate use of the Net.

Already, 17,000 ".com" names have been registered, and that number may swell to 50,000 a year from now, Walsh said.

A search of InterNIC’s public registry of names reveals several Fortune 500 companies whose names or products have been registered by someone else. Besides Cashel’s names, already taken are "coke.com," "startrek.com," "nasdaq.com," "cosmo.com" and "windows.com." Some companies have reserved scores of addresses that might be valuable someday, such as "pizza.com," "sex.com," "god.com" and "money.com."

Spokesmen for Hertz Corp., the Nasdaq stock market, Viacom Inc., Coca-Cola Co. and other companies and organizations contacted said they were unaware that the names had been registered. Several said the companies would investigate possible legal action to claim the names.

Like many legal issues in cyberspace, there is no clear precedent on whether traditional trademark law protection extends to Internet addresses.

"Addresses are problematic. The trademarks statute forbids the registration of geographic addresses, but computer addresses may not fall within those limitations," said Lynne Beresford, the trademark legal administrator at the U.S. Patent and Trademark Office.

"It’s very much like getting a vanity plate," said Jonathan Groves, manager of information services at the Internet Co., a Cambridge, Mass., Internet provider that registered the Nasdaq and Windows addresses for clients.

Several intellectual property and trademark lawyers said that companies whose names are taken may have pretty strong cases.

"Trademark rights are based upon use. If you make any other use of a name that could confuse the public, that’s trademark infringement," said John Hornick, an attorney who specializes in such matters.

"If you take an Internet address, you’re saying, ‘I’m going to take someone else’s name and register it,’ " he said. "You can certainly argue that might confuse the public, and could probably sue and win."

Merely registering a company’s name could prompt legal action, said Bruce Teller, outside counsel for the International Trademark Association. While not trademark infringement, registering a name could be considered trademark dilution because the commercial value in a name is diminished, he said.

Two cases are in the courts. In one, the MTV cable channel is suing Adam Curry, a former MTV host, over his use of the address "mtv.com." Curry originally offered to set up the address for MTV, but the network declined.

With MTV’s knowledge, Curry registered the name for himself and helped the network incorporate it into MTV programming. Only after Curry tried to stage an on-air resignation in April did MTV file suit to claim the name.

While the matter is in litigation, Curry has agreed to direct to another site users who try to address mtv.com.

Lawyers said the case probably will focus on MTV’s initial decision not to register the name, and not on trademark issues.

In the other case, the Princeton Review test preparation company registered the address "kaplan.com" in reference to its largest competitor, the Stanley H. Kaplan Educational Center. Although Princeton Review President John Katzman says the registration was a joke, the company activated the address with on-line advertisements for Princeton Review.

Kaplan, which is a unit of The Washington Post Co., filed suit. Kaplan President Jonathan Glayer said the company has since registered "about 20" variations on the Kaplan name and its products. The two companies have agreed to arbitration later in the year; in the meantime, Princeton Review has deactivated kaplan.com.

Princeton Review’s "joke" was certainly an expensive one. Katzman estimates his legal bills will run between $ 10,000 and $ 20,000.

Undeterred, he says he may have another joke in store for Kaplan. He’s considering registering the address "kraplan.com" and promoting it instead.

To avoid ending up in Kaplan’s position, companies can take preventive measures. Katzman himself urges, "Everybody should go out and register their company’s domain name right now."

Other suggestions from lawyers include trademarking an un-stylized company logo — because Internet addresses are plain text, a company’s stylized logo may not be admissible in an infringement case — and collecting evidence that a similar name causes public confusion. Misdelivered e-mail might be one way of documentation, attorney Hornick said.

Most of all, companies should not count on Internet providers to protect a name when someone else tries to register it — because most won’t.

"We can’t act as an arbiter," Internet Co. President Robert Raisch explains. "We would be placed in a position of qualifying every domain name for every country around the world."

Now a growing number of "community" or "civic" computer networks are springing up around the country to tie local people together and hook them into the Internet for free.

Last week, Maryland’s planned state-wide "Sailor" system, which makes the Internet’s so-called gopher services available at no cost, began limited operation in the Baltimore area. Officials hope to start making it available in Washington’s Maryland suburbs in September.

Sailor also will offer subsidized rates — $ 100 per year — for full access to the Internet, which is used by an estimated 20 million people worldwide. Commercial Internet services often charge three times that.

Sailor will join a more established Washington area community network, CapAccess, which in a year and a half has attracted more than 9,000 users by offering electronic-mail connections, limited access to the Internet and other services.

Since 1986 when Case Western Reserve University launched the Cleveland FreeNet, community networks have sprung up in many North American cities. The goal is to foster local communications and make sure that the poor and public service groups aren’t priced out of the electronic future.

They are free in the sense that public television is. People can sign up for nothing, but once aboard they are typically urged to donate money or time. Some services, such as Maryland’s Sailor, receive tax dollars.

"The whole idea of a civic network is new to everybody, including those who think they understand what it means," said Mark Bolgiano, a Greater Washington Board of Trade vice president who is studying a partnership with CapAccess.

"The number of people among our members who know what Internet is is still pretty low," he said. "CapAccess is even harder to understand."

Any area resident with a computer, modem device and communications software can reach CapAccess with a local telephone call. The number is 202-785-1523. Newcomers can log in under the name "guest", using "visitor" as the password.

People who already have Internet connections can reach CapAccess by using the telnet command to reach the address cap.gwu.edu.

Based at George Washington University, the service is geared toward helping users new to "the Net" get up to speed quickly. Instead of grappling with confusing typed commands, they can move around the service by picking numbered options from a menu or by typing shortcuts, such as "go post" to read e-mail.

There are on-line guides to appropriate Net conduct — dubbed "netiquette" — and other hints, such as how to select a good password. For users who would prefer face-to-face help, volunteers conduct free weekend training sessions.

CapAccess has targeted local schools, libraries, governments and social service groups by letting them use the service to promote their activities and collaborate with similar groups. Volunteers will help any such group post information or set up on-line "discussion groups" in which people carry on electronic dialogues.

Arlington County, for instance, has put a government information center on the system. The Montgomery County Public Library put its card catalogue on-line, and the Kennedy Center added performance schedules.

Several local schools put PTA minutes on-line and some churches have started posting sermons. Virginia Sen. Charles S. Robb set up a "virtual office," believed to be the first of its kind, which allows constituents to skim his voting record and official policy statements.

"It’s a good forum for people to look at what Senator Robb has been saying and doing," said Matt McGowan, Robb’s office manager.

The CapAccess experiment has created "new cross-community connections" between governments and community service groups, said CapAccess Executive Director Taylor Walsh.

"If there’s an information resource in Montgomery County that helps people who are homeless, there’s no reason for Arlington or Prince George’s to replicate that database and pay for its implementation if they can get access to it through the network," he said. "We’re already beginning to see that kind of thing happening."

Unlike many computer services, which tend to be used overwhelmingly by white males, the CapAccess user base is a fairly representative sampling of the region. At a recent membership meeting, half of the people attending were women, and almost a third were black. Overall, about 35 percent of CapAccess users are female, Walsh said. Only 10 percent to 15 percent of CompuServe and America Online users are women.

To provide true public access to the system, CapAccess has started a "recycling" campaign to refurbish old computers from corporations and governments and redistribute them to libraries, schools and community centers across the region.

"We need to put access points in the hands of the disadvantaged so [CapAccess] can be a tool for the many, not the few," said attorney Jack Young, a CapAccess volunteer.

Funded initially by grants from the Annenberg/Corporation for Public Broadcasting Projects with technical assistance from George Washington University, CapAccess now relies entirely on donations and volunteers such as Young to cover its $ 300,000 in annual costs.

This collaboration could serve as a model for national networks, users say.

"We are doing exactly what the government wants to do," said the Rev. Fred Williams, a board member. "Our ‘family’ is building a better community through technology. What we’re doing is replicable and exportable throughout the whole country."