Help:Tags

A tag (also referred to as a change tag) is....

Automatically applied tags
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Adding or removing tags from a revision or log entry
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Tag management
Users with the  user right (administrators by default) can use the Special:Tags special page to create, delete, activate and deactivate tags.

Creating a tag
You may create a new tag which will be applied manually by users. The name of the tag must satisfy the following criteria: To do this, use the form at the top of Special:Tags. (If you do not see the form, you do not have permission to create tags.) The reason you provide will be entered into the tag management log.
 * It must not contain the comma or forward slash  characters.
 * It must not contain characters that are prohibited in page titles (for example, ).
 * It must not be reserved by an extension.

Deleting a tag
If a tag is no longer wanted, you may delete it. This removes the definition of the tag from the database, and removes the tag from all revisions and log entries to which it is applied.

You cannot delete a tag that is defined by an extension, unless the extension specifically allows it. You also cannot delete tags with more than 5,000 uses, for performance reasons.

To delete a tag, click the "delete" link beside a tag. (If you do not see this link, the tag cannot be deleted.) Enter a reason, and click "Submit".

Activating or deactivating a tag
Users can only apply tags that are both user-defined ("Source" column shows "Applied manually by users and bots") and active ("Active" column shows "Yes"). For tags that are user-defined, you can use the "activate" or "deactivate" links to change the value in the "Active" column, thereby allowing or forbidding users to add the tag to revisions or log entries.

You cannot activate or deactivate a tag that is defined by an extension.