Deleted revisions and log entries will still appear in the page history and logs, but selected parts of their content will be inaccessible to the public. Please confirm that you understand the consequences and that you are doing this in accordance with the revision deletion policy (for administrators) or the oversight policy (for oversighters).
Warnings:
Redaction to hide block log entries or hide mere poorly considered actions, criticisms, posts, etc, outside these criteria and without required consensus, or agreement by the arbitration committee, will usually be treated as improper use and may lead to arbitration and/or desysopping.
Log redaction (outside of the very limited scope of criterion RD2 for the move and deletion logs) is intended solely for grossly improper content, and not permitted for ordinary matters; the community needs to be able to review users' block logs and other logs, whether or not proper.
Hiding the protection entry of creation protection for pages does not remove it from the publicly visible Special:ProtectedTitles. Should such entries need to be redacted, please unprotect the page; depending on the situation, it may also be appropriate to add a regular expression to MediaWiki:Titleblacklist.
Notes:
In case of redaction of log entries, please also check if any report pages need to have some revisions redacted.
In case of grossly offensive usernames please report the user to oversight who can reblock the user with 'hideuser' enabled, removing all logged occurrences of their name. Please also check the user's contributions and any edit summaries where they were reverted or reported.
In case of a page move, check the history of the page, since the move leaves edit summaries in the history. If an offensive title was used also consider the log of the title it was moved to. Additionally, if the page has any protection, check the protection log, since moving a protected page creates move log entries for the target.
In case of redaction of account creation logs, no need to redact anything but the username part. The action section is irrelevant.
RD5 and RD6 should be accompanied by additional clear explanation.