In the past week, reporters — like me — have pored over the most recent lobbying disclosures. We’re looking for stories about the revenue patterns at K Street’s notable shops.

But the best story may be what’s not in there.

If you’re curious about how business is for the ex-Obama administration officials who decamped for a shadow version of K Street, you won’t find a clue in the Lobbying Disclosure Act records.

Because these staffers do the kind of advocacy work that isn’t covered by the federal lobbying laws, such as grass-roots or public messaging, or because they spend less than 20 percent of their time on lobbying activities, they are free of the burdens of disclosure that compel their traditional K Street kin to reveal clients and fees.

“There is no doubt that there is this underground lobbying railroad where people aren’t registered, but they are involved in advocating on behalf of clients,” said Ivan Adler, a K Street headhunter with the McCormick Group.

Obama’s 2012 campaign manager Jim Messina runs the Messina Group, which bills itself on its website as “a full-service consulting firm” that uses its experience “winning campaigns and passing historic pieces of legislation to assist clients.”

Full-service does not include registered lobbying, apparently.

Others taking this path include former Health and Human Services official Dora Hughes, a senior policy adviser with Sidley Austin’s government strategies practice; Anita Dunn, a former Obama White House communications director, who is a managing director at SKDKnickerbocker; Nicole Isaac, a former special assistant to the president for legislative affairs, a principal with the D.C. firm theGroup.

The Obama administration did not invent the unlobbyist. Former lawmakers such as one-time Senate Majority Leaders Bob Dole, R-Kan., and Tom Daschle, D-S.D., and Speaker Newt Gingrich, R-Ga., resisted registering.

But the Obama message-makers made attacks on K Street a signature of the president’s campaigns, and the administration’s policies banning lobbyists from serving without a waiver or barring them from ever lobbying the Obama executive branch may have had the unintended consequence of pushing more advocacy work into the shadows.

“They literally ran the best message campaign in modern politics, and one of the central themes was cleaning up Washington,” said a registered lobbyist who requested to speak on condition of anonymity. “After six years, they didn’t go back to Chicago or wherever they came from, they stayed here in Washington. They employ lobbyists, and they work with lobbyists. I see no difference between what I do and what they do.”

Those who wish to overhaul the lobbying disclosure system to include more of the “unlobbyists” don’t necessarily agree on how to do it. Pretty much everyone does agree that the current laws lack enforcement.

Basically, unless you register as a lobbyist with the clerk of the House and the secretary of the Senate, no one knows you exist and no one comes after your time sheets to see if you are under that 20 percent threshold that triggers the LDA registration. (A lobbyist can also stay outside the system by making only one lobbying contact with a covered official.)

If the congressional officials in charge of administering the LDA hear of someone not reporting, they can refer the matter to the U.S. Attorney’s office. “With a few exceptions, that becomes a black hole,” said Tom Susman, director of the American Bar Association’s governmental affairs office.

Susman has been pushing Congress to lower the 20 percent threshold, but even he isn’t sure what precisely is the magic number. Maybe 10 percent. “It’s arbitrary,” he conceded. An alternative, he suggested, could be to do away with the time percentage and make it based on fees as a way to rope into the system grass-roots, media affairs and strategic advisers.

Craig Holman, a registered lobbyist with Public Citizen, said he’d like a professional investigative agency that could audit unregistered Washington policy advisers such as Daschle, who works at DLA Piper.

“The solution to the problem is not to get rid of all these ethics requirements,” Holman said. “The solution is to create an enforcement agency to enforce the law.”

Registered lobbyists already must report to Congress their campaign donations including high-dollar bundling activities because of lobbying law changes after the Jack Abramoff scandal. But Susman sees the Obama effect as a major factor.

“I don’t think people would have such hesitation to register if not for the Obama administration’s having handicapped lobbyists for employment, meetings, advisory panels,” Susman said.

And who wouldn’t just rather skip all the paperwork of disclosure and the branding as a lobbyist?

It just happens to leave the public — voters — unaware of the pressures on officials.

The opacity isn’t likely to ebb as more Obama administration officials head through the revolving door for the private sector during the president’s remaining years in office.

Just this month, Bart Chilton, who left his gig as a commissioner at the Commodity Futures Trading Commission, joined Daschle’s firm, DLA Piper.

Will Chilton represent some of the companies he regulated at the CFTC?

We may never know. A spokeswoman for the firm said he has no plans to register as a lobbyist.