STANFORD, Calif. - Students browsing the magazine shelves at Stanford University's Green Library might find pornographic material tucked between the current issues of "Playbill" and "Plays & Players."

The library carries recent issues of both "Playboy" and "Playgirl" magazines. After one year, the paper copies are discarded, but all back issues are available on microfilm in the library's Media Department.

"Green Library tries to document forces that shape the social and cultural life of this country and institutions that played a role in shaping American attitudes," said William McPheron, curator of British and American literature. "Since the 1960s, Playboy has been a visible and influential source in American cultural society," he said.

But the paper copies of both Playboy and Playgirl never stay on the shelf for long.

The magazines are stolen so frequently that the library is currently reviewing its decision to stock current copies of the magazine at all, librarians said.

"We're evaluating the decision to keep paper issues of Playboy because they don't last long enough on the shelf foranyone to use them," said Kathryn Kerns, the head of the information center at Green Library.

Assunta Pisani, associate librarian for collections and services, said the periodicals are chosen by different subject specialists representing areas of the University's academic interests. Green Library houses about 7,100 periodicals.

Under their classification, librarians said, Playboy and Playgirl fall under American literature.

McPheron said he believes the library has subscribed to Playboy since the 1960s and to Playgirl since the 1970s.

The library, however, does not subscribe to many other "pornographic" magazines, librarians said.

"We don't subscribe to a lot of other magazines like Penthouse, because these magazines don't have cultural prominence," McPheron said.

Theft of the magazines is a relatively new problem. Prior to the re-opening of the Bing Wing of Green Library in October 1999, all periodicals were kept in a separate area.

This room was staffed, and some magazines were held behind the desk and released only upon request.

McPheron said Playboy and Playgirl were not held in order to censor content, but because they had a high risk of being.

Now, the Current Periodicals section of the Green Library does not have its own room. These magazines are not held behind a desk and are more susceptible to theft.

Although the library does have some security precautions, including checking backpacks as patrons leave, most students said it's relatively easy to hide library material in binders or the bottom of their bags.

McPheron said he is disheartened by the current situation.

"Removing Playboy from the shelf is a good idea," he said. "It's not a matter of censorship, but of preserving material."

The Green Library's current policy, however, is relatively lenient. Pisani recalled working at Harvard University, where she said Playboy was "kept locked in a cage." To view the current issues or microfilm of Playboy and Playgirl one only needs entrance to the library with a student ID or "guest" card.

Since the material is not monitored, it's possible for underage patrons to view the pornographic pictures.

"This is a University, so we expect students of University age," Pisani said.

Both Pissani and Kerns are unsure if the University could be held legally responsible for making Playboy and Playgirl available to underage patrons.

This issue, they said, has never come up in the past. Many students, however, said they were unaware that the library had the magazines.

Those who had heard about the magazines thought such material should not be put on the library shelves.

"I think it is wrong," said senior Kevin Lim. "These magazines are pornographic and potentially offensive and should not be kept in public view."

Freshman Andrew Hwang agreed, and questioned the magazines' usefulness.

"Why would I need to go to the library to look at porn?" he said. "I have a computer."