Manual:Tags

Revision tags are annotations are automatically associated with an edit by the software. They can be displayed by the software in various locations when referring to revisions (such as in the page history, recent changes and other places).

A complete list of all different tags is available on Special:Tags.

Extensions (for example AbuseFilter and VisualEditor), mark edits made through their interface with tags.

Using tags from extensions
All tags used on at least one revision, and any tags listed by the ListDefinedTags hook, are shown on Special:Tags.

Two messages are associated with each tag:  is displayed on revisions with the tag, and   is additionally displayed on Special:Tags.

To add a tag to a revision, recent changes entry, or log entry, use. The RecentChange_save hook can be useful for this purpose.