uses are in active use.
&$tags: list of all active tags. Append to this array.
+'ChangeTagsAfterUpdateTags': Called after tags have been updated with the
+ChangeTags::updateTags function. Params:
+$addedTags: tags effectively added in the update
+$removedTags: tags effectively removed in the update
+$prevTags: tags that were present prior to the update
+$rc_id: recentchanges table id
+$rev_id: revision table id
+$log_id: logging table id
+$params: tag params
+$rc: RecentChange being tagged when the tagging accompanies the action or null
+$user: User who performed the tagging when the tagging is subsequent to the action or null
+
'Collation::factory': Called if $wgCategoryCollation is an unknown collation.
$collationName: Name of the collation in question
&$collationObject: Null. Replace with a subclass of the Collation class that
'LinksUpdateComplete': At the end of LinksUpdate::doUpdate() when updating,
including delete and insert, has completed for all link tables
&$linksUpdate: the LinksUpdate object
+$ticket: prior result of LBFactory::getEmptyTransactionTicket()
'LinksUpdateConstructed': At the end of LinksUpdate() is construction.
&$linksUpdate: the LinksUpdate object
$output: ParserOutput that is produced from the page
$engine: SearchEngine for which the indexing is intended
+'SearchResultsAugment': Allows extension to add its code to the list of search
+result augmentors.
+&$setAugmentors: List of whole-set augmentor objects, must implement ResultSetAugmentor
+&$rowAugmentors: List of per-row augmentor objects, must implement ResultAugmentor.
+Note that lists should be in the format name => object and the names in both lists should
+be distinct.
+
'SecondaryDataUpdates': Allows modification of the list of DataUpdates to
perform when page content is modified. Currently called by
AbstractContent::getSecondaryDataUpdates.