Federal agencies imposed "John Doe" gag orders on 53 new patent applications in fiscal 2007, bringing the total to 5,002, according to documents acquired by a government secrecy tracker.

Controls ranging from export restrictions to requirements for secure storage to curbs on even acknowledging the inventions exist were placed on the creators.

“It’s a fascinating side alley where technology intersects with policy and national security,” said Steven Aftergood, who directs the Project on Government Secrecy for the Washington-based Federation of American Scientists.

For inventors and any venture capital backers, the secrecy orders may not be entirely bad news, he said.

 “In many cases involving national security-related inventions, the government is their main or only customer anyway, so the secrecy order doesn't bother them too much,” said Mr. Aftergood, who responded to questions via e-mail and telephone.

A declassified 1971 memo obtained by the FAS from the Armed Services Patent Advisory Board gives an inkling of the types of patents Washington would like to keep under wraps.

A 26-page list includes items with obvious military applications like torpedo-propulsion systems, radiological warfare devices, and noise devices used in psychological warfare. Since that last was drawn up, however, some of the items, such as “computer-generated map image hardware and software” have moved into the civilian marketplace. A more recent list of patent secrecy categories remains under wraps, Mr. Aftergood said.

The Armed Services Patent Advisory Board was terminated in 1997, but its functions were shifted to the Defense Threat Reduction Agency.

Mr. Aftergood said little is known about how the secrecy orders, required under the Invention Secrecy Act of 1951, are applied.

“Almost by definition, inventors or companies don't publicize the fact that they are under a secrecy order,” he said.

Still, gag orders may not harm inventors and venture capital backers economically.

“In many cases involving national security-related inventions, the government is their main or only customer anyway, so the secrecy order doesn't bother them too much,” he said.

The total number of secrecy orders in effect has increased from 4,841 in fiscal 2003 to 5,002 in fiscal 2007. In fiscal 2007, 128 secrecy orders were imposed, 53 or them on private inventors. Of the 128 patent applications that prompted secrecy orders in fiscal 2007, in 68 cases, a gag order was imposed on the inventors, ordering them not to disclose details of their now-classified invention.

FAS obtained the statistics concerning Patent and Trademark Office secrecy orders through Freedom of Information Act requests.

FAS was formed in 1945 as an advocacy group by scientists who worked on the Manhattan Project, creating the first atomic bomb.