What is a redaction? Its definition and what it means for the Mueller report

As Americans on Thursday awaited the release of the full 400-page report from special counsel Robert Mueller's Russia investigation, many wondered about one catch: What's "redaction" mean, anyway?

Google searches to define the term skyrocketed Thursday ahead of the report, for which Attorney General William Barr warned redactions would be "required."

A redacted document is one "edited especially in order to obscure or remove sensitive information," Merriam-Webster notes, and that's just what the Justice Department said it's done: Its attorneys spent weeks poring over the report, blacking out certain information before it was made public.

"As you will see, most of the redactions were compelled by the need to prevent harm to ongoing matters and to comply with court orders," Barr said in remarks prepared for Thursday.

Two redacted versions of Mueller's report exist, in fact: one meant for the public on Thursday and a second, less-redacted version planned for a "limited number of members of Congress," per a Wednesday court filing.

More: Read special counsel Robert Mueller's report into President Trump, Russian interference

More: Donald Trump reacts to Mueller report: 'It’s called no collusion, no obstruction'

According to a Monmouth University poll, 60% of Americans want to see Congress get full access to Mueller's report, with just 30% saying the Justice Department should be able to redact info considered sensitive.

In a letter last month, Barr warned of "the redactions that are required" for the report, noting four types of information that would be censored: classified intelligence, grand jury testimony, information tied to ongoing investigations and information that would infringe on certain third parties.

Here's what each redacted category means, as noted in this very thorough explainer from PBS NewsHour:

  • Classified intelligence: Information that could hurt intelligence community methods and sources would be redacted, but could be made available to Congress.

  • Grand jury testimony: Information gathered by Mueller through a grand jury must be redacted per federal rules, though a judge technically could order its release.

  • Ongoing investigations: Information tied to the many investigations resulting from Mueller's Russia probe could become available after such investigations conclude.

  • Third parties: Information would be redacted about individuals not facing charges, or, as Barr has told lawmakers, "people in private life, not public office holders."

More: What do collusion and obstruction mean?

Follow Josh Hafner on Twitter: @joshhafner

This article originally appeared on USA TODAY: What is a redaction? Its definition and what it means for the Mueller report