The NYT takes a look at some heavyweight members of corporate America's tweaking of Wikipedia entries, either to make to make themselves look good or a competitor look bad.

Jimmy Wales, founder of the Wikimedia Foundation, which runs Wikipedia, says the site discourages such “conflict of interest” editing. “We don’t make it an absolute rule,” he said, “but it’s definitely a guideline.”

So what should big companies do if they want something changed?

Mr. Walton said ExxonMobil employees “are not authorized to update Wikipedia with company computers without company endorsement.” The company’s preferred approach, he said, would be to use Wikipedia’s “talk” pages, a forum for discussing Wikipedia entries.

Mr. Wales also said the “talk” pages are where Wikipedia encourages editors with a conflict of interest to suggest revisions.

“If someone sees a simple factual error about their company, we really don’t mind if they go in and edit,” he said. But if a revision is likely to be controversial, he added, “the best thing to do is log in, go to the ‘talk’ page, identify yourself openly, and say, ‘I’m the communications person from such and such company.’ The community responds very well, especially if the person isn’t combative.”

Mike Sitrick, a longtime public relations consultant in Los Angeles, agreed. “I’m a big believer that if you’re going to correct it, correct it with a name,” he said. “Otherwise it hurts your credibility.”