The New York City Police Department insists that its freedom of information handbook is confidential. Ask for the department's transparency guidelines, and the Freedom of Information Unit will unblinkingly reply that its own processes are immune from public disclosure.

In a February 28th letter, NYPD Records Access Appeal Officer Jonathan David affirmed the baffling rejection of my records request, submitted two months earlier, for the department's training materials and handbook on New York's Freedom of Information Law. Invoking attorney-client privilege, the records access officer ruled that a handful of statutes "prohibit disclosure" of freedom of information reference materials.

Dubious legal assertions aside—and there are many at play in his one-page letter—Officer David's decision underscores the NYPD's notorious resistance to public disclosure. Whether by unleashing its own "SECRET" stamp or by flouting even routine document requests from activists, reporters and concerned citizens, the department has eschewed transparency at every turn.

Yet the NYPD has lost their share of legal battles over document requests. In the last ten years, judges have ordered the NYPD to release stop-and-frisk data, hate crimes reports and gun permit applications, to name just three of many instances where police lawyers attempted to block disclosure in recent memory.

But this latest rejection is for the exact guidelines that spell out which records must be released and which can be withheld from the public. Few documents are better suited for release under the Freedom of Information Law than a freedom of information handbook.

Robert Freeman, executive director of the New York Committee on Open Government,a taxpayer-funded agency which oversees transparency matters across the state, agrees that police ought to release the guide.

"It is in the public's interest to know how the NYPD functions," says Freeman. "If this guide represents the policy of the department, it is not privileged."

Freeman also says that blanket denials like Mr. David's "don't make a hell of a lot of sense," since an agency can often release sections of documents even if they cannot publish the entirety.

Even federal intelligence agencies like the NSA and the FBI release their disclosure manuals upon request, or at least a portion. But the NYPD insists that the public has no right to inspect any part of its freedom of information procedures. Officer David has left me with no recourse save needless litigation to obtain even a single page.

This week is Sunshine Week, as transparency advocates and government officials across the country consider ways to reinforce principles of openness within our democracy, Mayor de Blasio and Commissioner Bratton can take a simple but powerful step toward transparency: Publish these procedures, without delay.

Few know the NYPD's dismal track record on freedom of information better than the mayor. Just last April, Public Advocate de Blasio gave the police a failing grade on openness. His report noted the department's failure to respond to nearly a third of records requests it received in a three-month period.

At the time, de Blasio recommended fining agencies that repeatedly undermine disclosure by delaying requests or otherwise violating New York's freedom of information statute. He also called on city agencies to proactively publish commonly-sought information online.

Since his own swearing in, NYPD Commissioner Bill Bratton has made a number of commitments to unprecedented transparency and a "collaboration unlike anything we've ever seen" between police and public.

"There should be no secrets in the NYPD," he told the Citizens Crime Commission on February 7. "We're going to do more to open up the organization"

The mayor and commissioner seem to be on the same, unredacted and publicly available page. They should invite records officers at One Police Plaza—and in every city agency—to join them. Releasing freedom of information standards is a great place to start.

Shawn Musgrave is the editor of MuckRock, an independent investigative news and open records startup based in the Boston Globe Media Lab.