User:Ostrzyciel/GSoC 2020/help

A revert is (broadly speaking) an edit removing some previous contributions from a page. It is usually used when combating spam, vandalism and removing other content that is considered unsuitable on your wiki.

MediaWiki provides multiple methods of reverting changes, along with additional features that will help you keep track of reverts and reverted edits.

Revert methods
This section describes all revert methods provided by MediaWiki by default. Extensions and gadgets may add more revert methods.

Manual revert
A manual revert is performed by simply editing a page and manually removing parts of it. You can also pick a previous revision from page's history and, while viewing it, click the edit button. This will let you base your edit on that previous revision that does not contain undesirable content.

Manual revert tag
Todo: screenshot with the tag

MediaWiki will automatically mark manual reverts with the mw-manual-revert change tag, if they restore the page to an exact previous state. In order to do this, MediaWiki compares the new edit's content to recent edits on the page and tries to find an exact match.

The amount of recent edits that will be checked is configurable (through the  variable) and by default set to 15. See m:Research:Revert for a discussion on this topic and links to papers that led to choosing 15 as the optimal value.

Undo
Todo: screenshots

Undo allows you to revert any change from page's history. The reverted edit does not have to be the latest, MediaWiki will automatically try to merge the current and reverted-to revisions. In case the merge fails, an error message will be displayed and you will have to remove the unwanted content manually.

Undoing multiple revisions
Todo

Undo tag
Prior to version 1.36 all edits that were started using the undo link were marked using the mw-undo change tag.

Since 1.36 only undos that are a product of the automatic merge and were not modified by the user before saving are marked using the mw-undo tag.

Rollback
Todo: screenshot

A rollback reverts all recent changes made to a page by one user.

This feature is only available to users with the  user right.

Rollback tag
All rollbacks are automatically marked using the mw-rollback change tag.