That's the big question as special counsel Robert Mueller wraps up his investigation into Russian meddling in the 2016 election. But there's remarkably little precedent for how exactly he should close the case and issue a final report.

Mueller is only the second special counsel in US history appointed under the current Justice Department rules. Those binding regulations, written in 1999, spell out what is supposed to happen at the end of an investigation. White House lawyers, Democrats on Capitol Hill and just about everyone in between are parsing the language anew, and the issue is far from settled.

The rules require Mueller to submit a "confidential report" at the end of the investigation to Attorney General Bill Barr. After that, Barr must send his own notification to Congress, letting them know that the investigation is over. Barr has pledged to "provide as much transparency as I can," but hasn't committed to publicly releasing the entirety of Mueller's confidential report.

WASHINGTON, : US Attorney General Janet Reno arrives to speak to a crowd of reporters at the US Department of Justice 03 September, 1999 where she announced that she will name an independent investigator outside the Justice Department to look into questions surrounding the FBI's 1993 assault on the Branch Davidian compound near Waco, Texas. Reno's announcement comes in the wake of recently released FBI video tapes on which permission is given to fire and incindiary grenade that may have caused the fire that killed 80 Branch Davidians including their leader David Koresh. AFP PHOTO/ JOYCE NALTCHAYAN (Photo credit should read JOYCE NALTCHAYAN/AFP/Getty Images)

Plenty of special prosecutors have previously investigated everything from Watergate to the Lewinsky affair, but they worked under different circumstances and regulations. These are uncharted waters.

The only existing direct comparison to Mueller dates back to 1999, when Attorney General Janet Reno named a special counsel to investigate the deadly Waco standoff and allegations of a government cover-up. It worked under the same rules as Mueller.

But those prosecutors didn't wait around for Justice Department higher-ups to examine their final product. They posted their full report directly onto the burgeoning Internet, along with hundreds of pages of detailed exhibits and timelines. In interviews with CNN, former special counsel Jack Danforth and his deputy encouraged Barr to follow their lead when it comes to transparency.

Lessons from special counsel past

By the time Danforth, a former GOP senator from Missouri, was appointed, six years had passed since the deadly April 1993 confrontation between US law enforcement and members of a religious cult in central Texas.

Public discourse about the incident was dominated by accusations that the government started the fire that killed dozens of cult members, including children. Over time, the FBI changed its story on the use of pyrotechnic devices, and conspiracy theories flourished. A sitting member of Congress accused the Clinton administration of orchestrating the tragedy to pass gun control measures.

Reno specifically encouraged Danforth to tailor his work toward a public report, going beyond the regulations that were ratified under her watch a few months earlier.

"In addition to the confidential report requirement... the special counsel, to the maximum extent possible and consistent with his duties and the law, shall submit to the Attorney General a final report, and such interim reports as he deems appropriate, in a form that will permit public dissemination," Reno wrote in September 1999

That's a key difference from Mueller. When Deputy Attorney General Rod Rosenstein appointed Mueller in 2017, he was given wide latitude to investigate Russian meddling but told to stick to department rules, which say nothing about the special counsel releasing a public report.

Even without that specific authorization, Danforth, asked about how he interpreted the regulations, says transparency should be paramount.

"Mueller was given a specific charge (to investigation Russian meddling), not to just investigate whatever he wants," Danforth said. "Let's leave no doubt in the public's mind what his findings are on that charge. But if it's getting into stuff unrelated to that charge and matters where he doesn't have evidence beyond a reasonable doubt, my impression is that shouldn't go public."

When Danforth wrapped up his investigation in November 2000, his team went directly to the American people and posted their final report on their now-defunct website, www.osc-waco.org. They had already publicly announced their preliminary findings in a 153-page interim report

Ed Dowd, deputy special counsel in the Waco probe, said "the goal was to be as transparent as we could possibly be." This is the same objective Barr laid out to lawmakers earlier this year.

"We're talking about whether a candidate for president was co-opted by a foreign government," Dowd said.

"Obviously, the people of this country are entitled to this information. And I'm sure Robert Mueller will try to give us as much information as he can, and hopefully the new attorney general will too," he added. "I just really hope he gives the American people what they're entitled to."

Poring over the regulations

With Mueller's work nearly finished, the next phase of this saga is the fight over the report.

Two little-noticed provisions in the Code of Federal Regulations are now at the center of the debate. They dictate how the special counsel should produce reports and how the attorney general should keep Congress -- and sometimes the public -- informed about the investigation.

Additionally, existing laws prohibit disclosure of grand jury proceedings without a court order. Mueller has extensively used his grand jury to gather evidence from more than 20 witnesses including Trump campaign chairman Paul Manafort and attendees of the 2016 Trump Tower meeting.

"During our investigation, we tried very hard not to use the grand jury whenever possible, so that we weren't constrained by the rules and laws that apply to grand jury secrecy," said Jim Martin, another prosecutor on the Waco team, explaining their exhaustive effort to keep the public informed.

JUST WATCHED Danforth: Trump has 'corrupted' GOP Replay More Videos ... MUST WATCH Danforth: Trump has 'corrupted' GOP 00:43

CNN reported Thursday some Trump administration officials believe the Justice Department regulations don't explicitly authorize the attorney general to release Mueller's confidential report. These administration officials believe the rules, as originally written, actually protect the President from any negative information being released if he is not charged with a crime.

The young Justice Department attorney who wrote those rules, Neal Katyal, disputed that assessment on CNN's "AC360." He went on to become a top Obama administration lawyer.

"It's totally inconsistent with the special counsel regulations, which are all about, at their heart, providing public confidence in the administration of the rule of law," Katyal said Thursday.

It's still unclear how Barr will handle the situation, and legal experts say he has wiggle room

Naming names of wrongdoers

Another sticking point: What should the Russia report reveal about President Donald Trump or any of his associates that were found to have done something wrong but not in a criminal way?

Trump's allies have found solace in recent comments from Barr and Rosenstein extolling the virtue of protecting uncharged individuals by keeping "derogatory information" out of public view. That is the Justice Department policy after all.

In the Waco probe, Danforth only brought criminal charges against one person, a former DOJ lawyer accused of obstruction of justice. But in the final report named additional department officials who misled investigators, and the report recommended that those people should be demoted.

"I have thought long and hard about the fairness of publicly criticizing people whom I will not prosecute," Danforth said in a letter to then-Deputy Attorney General Eric Holder, who oversaw the investigation. "My primary responsibility has been to find the facts... and publish my findings in a report for public dissemination. My prosecutorial role was secondary to this obligation."

In a recent interview, Martin added, "transparency dictated our decision to air that out."

When the dust settles on the Russia investigation, the American people should accept the findings and move on, Danforth said. Congressional Democrats shouldn't launch new investigations "into everything under the sun," added Danforth, a former Republican senator.

"I'm a Never-Trumper, but I think you're overdoing it with endless investigations," Danforth said. "It doesn't seem fair if it's years of open-ended investigations into Trump with infinite resources."