+'ChangeTagAfterDelete': Called after a change tag has been deleted (that is,
+removed from all revisions and log entries to which it was applied). This gives
+extensions a chance to take it off their books.
+$tag: name of the tag
+&$status: Status object. Add warnings to this as required. There is no point
+ setting errors, as the deletion has already been partly carried out by this
+ point.
+
+'ChangeTagCanCreate': Tell whether a change tag should be able to be created
+from the UI (Special:Tags) or via the API. You could use this hook if you want
+to reserve a specific "namespace" of tags, or something similar.
+$tag: name of the tag
+$user: user initiating the action
+&$status: Status object. Add your errors using `$status->fatal()` or warnings
+ using `$status->warning()`. Errors and warnings will be relayed to the user.
+ If you set an error, the user will be unable to create the tag.
+
+'ChangeTagCanDelete': Tell whether a change tag should be able to be
+deleted from the UI (Special:Tags) or via the API. The default is that tags
+defined using the ListDefinedTags hook are not allowed to be deleted unless
+specifically allowed. If you wish to allow deletion of the tag, set
+`$status = Status::newGood()` to allow deletion, and then `return false` from
+the hook function. Ensure you consume the 'ChangeTagAfterDelete' hook to carry
+out custom deletion actions.
+$tag: name of the tag
+$user: user initiating the action
+&$status: Status object. See above.
+
+'ChangeTagsListActive': Allows you to nominate which of the tags your extension
+uses are in active use.
+&$tags: list of all active tags. Append to this array.
+