Special counsel Robert Mueller's report, with redactions, as released on Thursday, April 18, 2019, is photographed in Washington. Credit: Jon Elswick | AP

Attorney General William Barr’s office grouped redactions into four categories. The vast majority of redactions were material from grand jury proceedings, kept secret by law, or details whose public disclosure could jeopardize ongoing investigations. To a lesser degree, material was redacted if it could “compromise sources and methods” used in intelligence gathering or would “unduly infringe on the personal privacy and reputational interests of peripheral third parties.”

The first volume of the report, which deals with the special counsel’s investigation into Russian interference in the 2016 election, is the most heavily redacted. It contains almost all of the report’s grand jury redactions. The second volume, which deals with the question of whether President Trump obstructed justice, was most often redacted because of harm to ongoing investigations.

While there are redactions throughout the report’s two volumes and four appendices, some are more heavily redacted than others. Below are highlights.

Volume 1, Section 2

Russian “active measures” social media campaign

The report’s first large block of redactions is in a section explaining attempts by the Internet Research Agency to influence the U.S. election using social media. The Russian group with Kremlin ties allegedly set up thousands of accounts on Twitter, Facebook and other social media outlets that posted content in support of Trump’s campaign.

In February 2018, 13 Russian individuals and three companies were indicted and face charges including conspiracy to defraud the United States. Much of the unredacted information in this section is also seen in their indictment, and the redactions categorized “harm to ongoing matter” may be related to that ongoing case. However, as Russia does not allow its citizens to be extradited to the United States, it is unlikely that these individuals will face a trial.

Volume 1, Section 3

Russian hacking and dumping operations

Most of the “investigative technique” redactions occur in the section of the report on an alleged Russian operation to hack the Clinton campaign and the Democratic National Committee, which led to the release of stolen documents.

These redactions might refer to U.S. counterintelligence websites, sources or methods of investigating the hacks. There are also redactions in this section that appear to protect the Twitter handles and email addresses of individuals, some of whom were involved in the Trump campaign.

Several harm to ongoing matter redactions at the end of this section relate to the Trump campaign’s “interest in WikiLeaks’s releases of hacked materials” and may involve Trump campaign adviser Roger Stone, who has pleaded not guilty to charges of lying, obstruction and witness tampering. Stone’s indictment describes an effort to coordinate with WikiLeaks during the campaign and aligns with some of the events in this section.

Volume 1, Section 4

Russian links to the Trump campaign

This section of the report describes interactions between the Trump campaign and the Russian government. There are redactions throughout, most of which come from grand jury proceedings.

The portions regarding campaign adviser Carter Page and a June 9, 2016 meeting at Trump Tower are the most redacted in this section.The meeting, which Donald Trump Jr. helped coordinate, involved a Russian attorney and senior members of the Trump campaign, including chairman Paul Manafort and senior adviser Jared Kushner. The report reveals new details about the meeting, but many were redacted.

Volume 2, Section 2

The president’s conduct toward key associates

This section deals with Trump’s conduct involving Michael Flynn, Paul Manafort and a person whose name was redacted as a precaution against harm to ongoing matters. The redacted person appears to be Roger Stone, who will face trial for lying, obstruction and witness tampering in November. On page 128 of volume 2, a footnote contains a redacted a portion of a CNN headline about Stone. Another footnote on 151 reveals that a redacted paragraph seems to be a Dec. 3, 2018, tweet from the president, which references Stone.

Appendix D

Referred and transferred cases

The fourth appendix to the report lists criminal cases that came out of the investigation. Two ongoing cases of the 11 that were transferred to other jurisdictions have been redacted. The other nine cases include the charges against Michael Flynn, Richard Gates, Paul Manafort and others.

The special counsel’s office also found evidence of potential wrongdoing but did not issue charges in 14 other instances that it referred to other authorities. The names of individuals involved and descriptions of wrongdoing are redacted in 12 of these 14. But the list is in alphabetical order, which narrows the possibilities of just whose names are hidden: One comes before Cohen, and two come between Cohen and Craig.

Washington Post writer Armand Emamdjomeh contributed to this report.