The Defense Department is still casting about for ways to put a secrecy stamp on technological information even when its disclosure would not cause "damage to the national security."

One proposal contained in a study submitted to the Pentagon last month would have the secretary of defense proclaim such disclosures "damaging" anyway and classify the data as "confidential."

Officials say that such a step might seem a bit too bold and assertive, however, especially in light of the Pentagon's acknowledgment more than a year ago that the information at issue was not crucial enough to be labeled "confidential" and would require a new, less rigorous, security classification.

There is no such lower level of secrecy under current regulations. The existing security classifications--top secret, secret and confidential--have been in force since President Eisenhower's first year in office.

In 1981, Defense Secretary Caspar W. Weinberger tried to get President Reagan to sanction a new classification of "restricted." Weinberger argued that it was critical to "the effective safeguarding of a range of information that is not now generally classifiable." The idea was rejected at the White House.

Reagan subsequently issued a controversial executive order prescribing much more secrecy in the field of national security, but the "confidential" classification still had a tighter definition than the Pentagon wanted. It is supposed to be applied only to documents the unauthorized disclosure of which can reasonably be expected to cause "damage to the national security."

What the Pentagon wants to restrict, simply put, is "unclassified technology with military application."

Critics say that this could give Defense Department officials the power to censor the know-how behind tens of thousands of commercial items, from chess-playing computers to air conditioning machines.

At stake, it appears, is "the technical data" for items on the Commerce Department's Commodities Control List, which is used in determining what items may be exported to which countries--if at all. According to Allen Adler of the privately funded Center for National Security Studies, such technical data could mean "information of any kind that can be used or adapted for use in the design, production, manufacture, utilization or reconstruction of articles or materials" falling within 10 basic categories.

What bothers the Pentagon is that such information in the government's possession is subject to release under the Freeedom of Information Act unless it can be classified legitimately as top secret, secret or confidential or withheld under some other FOIA exemption, such as the one protecting trade secrets.

According to a 67-page report submitted last month to the Defense Department's Office for Counterintelligence and Security Policy, one solution could be a bill in which Congress explicitly declares that "public disclosure of information subject to export control laws is tantamount to export . . . . Therefore, that information, such as technical data related to items on the Munitions Control and the Commodities Control lists, may be excluded from public disclosure."

Another route suggested in the report would be a bill authorizing the secretary of defense to prescribe regulations protecting unclassified information "originated by or on behalf of" the Defense Department if its disclosure "could reasonably be expected to result in the loss of a significant military technological or operational advantage of the United States."

Arthur Fajans, acting director of the Pentagon's directorate for information security, said draft legislation incorporating this proposal has been submitted to the Office of Management and Budget. "The way we would handle it," he said, "would be to apply a 'For Official Use Only' " label to such material.

It was learned, however, that the bill has been sitting at OMB since December and is not likely to get any further. "There are a lot of reservations about it," said one knowledgeable administration official. Mainly, he said, "it's just an overreaching of power" on the part of the Defense Department.

The 67-page study said the Defense Department was also studying the possibility of going ahead on its own and applying a "confidential" classification to such materials but with less expensive safekeeping and security-clearance requirements than those normally attached to "confidential" documents.