This page lists the tags that the software may mark an edit or logged action with, and their meaning. See Wikipedia:Tags.
Administrators are able to perform different actions in respect to tags, including deleting some of them; please refer to the section on tag management in the documentation for indications.

Tag nameAppearance on change listsDescriptionSourceActive?Tagged changes
visualeditorVisual editEdit made using the visual editorDefined by the softwareYes36 changes
visualeditor-switchedVisual edit: SwitchedUser started to edit using the visual editor, then changed to the wikitext editor.Defined by the softwareYes4 changes
mw-undoUndoEdits that undo previous edits using the undo linkDefined by the softwareYes4 changes
mw-rollbackRollbackEdits that roll back previous edits using the rollback linkDefined by the softwareYes2 changes
mw-replaceReplacedEdits that remove more than 90% of the content of a pageDefined by the softwareYes1 change
mw-contentmodelchangecontent model changeEdits that change the content model of a pageDefined by the softwareYes0 changes
mw-new-redirectNew redirectEdits that create a new redirect or change a page to a redirectDefined by the softwareYes0 changes
mw-removed-redirectRemoved redirectEdits that change an existing redirect to a non-redirectDefined by the softwareYes0 changes
mw-changed-redirect-targetRedirect target changedEdits that change the target of a redirectDefined by the softwareYes0 changes
mw-blankBlankingEdits that blank a pageDefined by the softwareYes0 changes
visualeditor-wikitext2017 wikitext editorEdit made using the 2017 wikitext editorDefined by the softwareYes0 changes
visualeditor-needcheckVisual edit: CheckEdit made using the visual editor where the system detected the wikitext possibly having unintended changes.Defined by the softwareYes0 changes
massmessage-deliveryMassMessage deliveryMessage delivery using Extension:MassMessageDefined by the softwareYes0 changes