Modern journalistic ethics say that reporters should identify themselves and their purpose when working on a story, with one notable exception -- restaurant reviews.

Anonymity is a tool of the trade for dining critics because reviewers have to get the same treatment as any other diner. If restaurateurs knew a critic was in the house, they might provide a higher caliber of food and service than they do for the average customer.

For this reason, dining critics take great care to conceal their identities, using other names when they make reservations and on their credit cards. They've also been known to wear disguises, the most famous and extreme example being former New York Times dining critic Ruth Reichl, who developed a whole stable of personas with different wigs, walks and voices.

In two recent cases, however, critics' anonymity is under attack, and food writers worry that the disputes are bad for the profession.

Craig LaBan, dining critic for the Philadelphia Inquirer for the past 10 years, was sued earlier this year for libel after he described a $15 piece of beef as "miserably tough and fatty" at Chops restaurant in Bala Cynwyd. Under orders from a judge, Mr. LaBan had to give a videotaped deposition that would reveal his identity if it ever got out, as videotape tends to do in the age of YouTube.

The lawsuit is ongoing, so Inquirer editor Bill Marimow would say only this: "When all is said and done, the case will demonstrate that Craig LaBan is a stellar reporter, meticulous, fastidious and a very fair restaurant critic. What he wrote is classic opinion."

In the second case, at The Gazette of Colorado Springs, Colo., the dining critic is the subject of an outing campaign by the alternative weekly newspaper.

The critic writes under the pseudonym of Nathaniel Glen because when he was chosen for the job several months ago, he already was a staff writer covering other subjects. As such, his face and name have appeared in the paper and on its Web site.

The Colorado Springs Independent has run two articles criticizing the pseudonym, charging that it allows the critic to take potshots without answering for them. The weekly has hinted at his identity in the form of rhymes and anagrams -- all based on information from unnamed sources, which strikes officials at The Gazette as most ironic.

"As long as the pseudonym is not hiding a conflict of interest, readers don't care what name a reviewer uses," said Warren Epstein, entertainment editor of The Gazette.

Absent charges of impropriety, he said, "What is the journalistic reason for one paper outing another paper's critic? To me it's just evil, pure and simple. It doesn't serve anybody. Maybe it's just the alternative press wanting to stick it to the man, but they're sticking it to people who are their readers as well."

Ralph Routon, executive editor of the Independent, said he took no issue with the critic's abilities, only with the paper's refusal to identify him. He denied that the outing campaign is sour grapes.

"I wouldn't be in favor of us ever publishing the guy's mug shot," Mr. Routon said. "But a person's byline doesn't make that person known to everyone in the community. We use several reviewers whose names are well known and their ability to do their job has never been compromised."

These situations are troubling, according to Carol DeMasters, director of the Association of Food Journalists, which has an ethics policy that stresses the need for anonymity.

"There are restaurant critics in other papers who use pseudonyms -- very few, but there are some," said Ms. DeMasters.

(The Post-Gazette is among them. Former restaurant critic Elizabeth Downer uses her unmarried name, and the Munch reviews of local eateries have been written by a variety of staffers over the years.)

In the Colorado case, Ms. DeMasters said, since the critic already was known as a reporter before becoming restaurant critic, "adopting a pseudonym is the best way to handle it.

"If he were to use his real name, there would be no anonymity. So it seems to me like they [at the other paper] want to do him in.

"I would think they'd have better things to do," she added. "Newspapers are in enough of a precarious financial situation. The last thing readers like to see is journalistic backbiting."

As for the Philadelphia situation, she said, a lot depends on the judge's motive for requiring a taped deposition. If the judge orders videotape on all such testimony, that's one thing; if it's just this case, that's more disturbing.

Robert Steele, senior ethics faculty at the Poynter Institute for journalistic ethics, likened restaurant reviews to inspections in the military.

"If you know the colonel's coming to the barracks, you're going to spiff it up," he said. "Journalistic honesty is always important, but it's a common-sense agreement that to do a genuine, independent review, it needs to be done without the knowledge of the restaurant."

As for the First Amendment issue, Mr. Steele said, newspapers have to pick their battles.

"We should always do our best to protect the legal rights of journalists. At the same time, restaurant reviews are not the kind of significant watchdog journalism that holds the powerful accountable.

"I don't think we should throw critics under the wheels of the truck, but because of how much it costs and the chance it could create bad case law, there are times we choose certain territory to more vigorously defend."