The unusual directive, known as a CANFORGEN, was written last year by the country's deputy top commander in response to a media story on financial uncertainty facing National Defence.
The story, in the Ottawa Citizen on April 29, 2011, looked at lapsed funding — cash the department was unable to spend on capital projects — and came at the height of the last federal election campaign.
It was deemed to have contained "information that was not meant for wider or public consumption," but the data had not been given the designation of either secret or protected.
That prompted Vice-Admiral Bruce Donaldson, the vice chief of defence staff, to instruct those handling information to give everything that passes over their desks — or posted on the internal department system — a second glance with an eye to keeping it hidden.
"Information that is not sensitive to the national interest, and therefore not classified, should also be examined to see if it is sensitive to other than the national interest, and therefore requires an appropriate designation of either Protected A, B, or C," said the directive, obtained by The Canadian Press under the Access to Information Act.
The directive goes beyond reviewing information to protect privacy.
"Sensitivity to other than the national interest is not limited to information that is personally sensitive, but also includes, for example, information that sensitive to the organization, administration, finances or other internal functioning of the department, its relationship to outside organizations, or other government business operations."
Daniel Blouin, a defence spokesman, stood by the directive in an email statement. A directive is considered an order to members of the Forces, he said, and "DND is committed to safeguarding sensitive information, and to the safety of its people, assets and infrastructure."
Critics were surprised by Donaldson's directive, suggesting it was aimed at protecting the department and the Harper government from embarrassment.
"It looks very political," said Liberal Senator Colin Kenny, former head of the Senate defence and security committee. "My first reaction is that they want to protect the political interests of the government of the day, and that's not their job."
New Democrat defence critic Jack Harris has asked the information commissioner to investigate to determine whether the directive has violated the country's Access to Information Act.
"This is a department that spends 20 billion of taxpayer dollars annually and in terms of the documents available to the public, they seem to be seeking the highest degree of secrecy based on vague notions," said Harris.
"It's contrary to the public interest and contrary to the principles of accountability that this government claims to hold dear."
The Defence Department has been embarrassed on several occasions by the inadvertent leak of information. A few years ago, news of an investigation into the country's special forces in Afghanistan slipped through the filter because of an access-to-information request.
The department was, at the time of the Citizen story, in the middle of revamping the way it deals with information and planned to introduce a new defence security plan, as well as an updated defence and security manual.
"These documents will reflect changes to the Government of Canada information assurance standard, and will be accompanied by a revitalized security education, training and awareness programme as an integral part of the department's security renewal campaign," said the Dec. 11, 2011, directive.
The flow of information to the public from National Defence has been eroding since 2007. Back then, the Conservatives insisted that all information and interviews requests of "national or regional importance" be flagged to the Privy Council Office, the bureaucratic arm of Prime Minister Stephen Harper's office.
The process has become routine and even expanded to the point where "the Centre," as it's referred to in government circles, gives its blessing to email talking points that substitute for interviews with government officials.
Kenny says the directive is part of a wider trend within government of shutting down access and not answering questions.
If enforced to the letter, Kenny says, the directive could have sweeping implications.
"This is could cause every document created by the Department of National Defence to be classified and that's a pity because Canadians are entitled to have an understanding of what goes on," said Kenny, a lawyer and former principle secretary to prime minister Pierre Trudeau.