The much-anticipated Mueller report released to the public Thursday contained more than 900 redactions, with seven entire pages blacked-out completely.

Attorney General William Barr said the version of the report released to the public would redact information based for four reasons, which would be color-coded to indicate why the information was being concealed.

Here is a breakdown of the redactions in the Mueller report, counted by each instance one of the four categories were used.

Harm to an Ongoing Matter

The most common redaction category throughout the 448-page report, with more than 400 instances, was categorized as “harm to an ongoing matter.” In remarks ahead of the report’s release, Barr said, “Most of the redactions were compelled by the need to prevent harm to ongoing matters and to comply with court orders prohibiting the public disclosure of information bearing upon ongoing investigations and criminal cases.”

Those cases could include the ones against Roger Stone and the Russian Internet "troll farm," the Internet Research Agency, Barr said.

The section of the report dealing with the investigation of Russian meddling into the election has more extensive redactions than the section relating to potential obstruction of justice, which is lightly redacted.

Grand jury

Information redacted because it was grand jury material was the second most common with more than 350 instances. Grand jury material is protected as part of the Federal Rules of Criminal Procedure, Rule 6(e), and Mueller used grand juries to issue subpoenas and search warrants throughout the probe.

Investigative technique

There were nearly 100 instances of redactions related to "investigative techniques," or information that could disclose secret intelligence sources and methods.

Personal privacy

According to Barr, the more than 70 "personal privacy" redactions were intended to block information that infringed on the privacy rights and reputation of "peripheral third parties."

Seven pages in total were redacted, listed as: 38, 65, 185, 186, 197, 341, 342.

Some prominent Democrats criticized Barr's decision to issue a redacted version of the report to Congress.

“The Attorney General’s decision to withhold the full report from Congress is regrettable, but no longer surprising," House Judiciary Committee Chairman Jerrold Nadler, D-N.Y., said in a statement. "If he was willing to release this evidence, which is so clearly damaging to the President, just imagine what remains hidden from our view."

Democratic hopeful Kristen Gillibrand, D-N.Y., called on the attorney general to “deliver the fully unredacted Mueller report to Congress because our job is to review it and he should make the facts available to the American public.”

Rep. Don Beyer, D-N.J., tweeted a photo of several pages of the report that were almost completely blacked out with redactions.

Actual pages of the Mueller report as redacted by Attorney General Barr: pic.twitter.com/scXvesrdjE — Rep. Don Beyer (@RepDonBeyer) April 18, 2019

NBC News and MSNBC legal analyst Danny Cevallos noted most of the categories were discretionary.

“There are less than I think people expected and also it’s important to recognize that of those four categories, three of them are discretionary by the attorney general, everything but the grand jury,” said Cevallos.

“Every other redaction other than grand jury redactions could theoretically be disclosed by the attorney general, if he so desired, to Congress,” Cevallos said.

In a court filing Wednesday in the special counsel's criminal case against Stone, Department of Justice lawyers told a judge that a less-redacted version of the Mueller report would be made "available for review by a limited number of Members of Congress and their staff" at some point. It doesn't specify which redactions would be lifted.