House Republicans have sent detailed perjury allegations against Hillary Clinton to the U.S. attorney for the District of Columbia, accusing the Democratic presidential nominee of lying under oath during congressional hearings. The group of Republicans, with 83 days (and counting) left before Clinton faces Republican challenger Donald Trump in the general election, are charging that her sworn testimony last year was inconsistent with what she told the FBI on the subject.

Here’s what you need to know.

What Is The Specific Controversy Now?

This isn’t the first time that House Republicans have accused Clinton of misusing the emails. These latest allegations come after the Benghazi Select Committee analyzed the former secretary of state’s actions around the Sept. 11, 2012, terrorist attacks in Benghazi, Libya. It found no new evidence of wrongdoing in June.

But, Republicans — primarily House Oversight Committee Chairman Jason Chaffetz, of Utah, and Judiciary Committee Chairman Bob Goodlatte, of Virginia — still think something’s fishy. According to the new complaint, Clinton testified under oath on Oct. 22, 2015, when she said there were no classified emails sent from the private email server that she had set up at the time.

Chaffetz and Goodlatte allege that Clinton failed to turn over all of her work related emails — and told Congress she had done so — after her lawyers combed through them.

Were There Classified Emails Sent From Her Server?

The FBI found announced this year that she had sent emails containing classified information but recommended against charging her with a crime because there wasn’t enough evidence to show she had intentionally mishandled classified information.

FBI investigators found 113 emails containing classified emails and three that had explicit classification markers. Another 2,000 of her emails contained information that was retroactively classified after the emails were first sent.

Are There Different Levels Of Classification?

Yes, and claims that the U.S. government frequently over-classifies documents are common. In those instances, the information wouldn’t actually damage national security if they were made public. There is some disagreement between the State Department and intelligence agencies on what documents should be classified. Some of Clintons emails are included in that dispute.

President Barack Obama, Clinton’s boss at the time, has defended her. He says that she wouldn’t intentionally put American security at risk. He has also mentioned the differences in classification.

“And what I also know, because I handle a lot of classified information, is that there are -- there’s classified and then there’s classified,” Obama said earlier this year. “There’s stuff that is really top secret, top secret and then there is stuff that is being presented to the president or the secretary of state that you may not want on the transom, or going out over the wire, but is basically stuff that you can get in open source.” 

Did Clinton Break From Protocol Using The Server?

State Department policy since 2005 says that all day-to-day operations need to be conducted through an official State Department channel. To set up a private server she and her team would’ve needed to peak with several internal offices, which she did not do.

Why Is This Whole Thing A Big Deal?

Republicans are concerned that she acted to try and keep secret her dealings while secretary and have expressed concerns over her reaction to the Benghazi attacks (many congressional committees have investigated this and haven’t come up with too much). Democrats say their Republican colleagues are on a partisan witch hunt, trying to take down their party’s presidential nominee.

But there are security and legal concerns. There were no signs that her server was hacked while she used it. But not having these emails on an official channel would and did make it more difficult for government investigators to access the emails. In addition, the practice would have made it difficult for people filing Freedom of Information Act requests — all government email is owned by the public — to receive their requests.

As for the most recent allegations, House Republicans say she lied under oath, or committed perjury. A guilty verdict (if the case is taken up in court) could lead to a fine or imprisonment up to five years. Again, legal experts say that would likely rely on showing intent.