$output: $wgOut
$term: Search term specified by the user
-'SpecialSearchResults': Called before search result display when there are
-matches.
+'SpecialSearchResults': Called before search result display
$term: string of search term
&$titleMatches: empty or SearchResultSet object
&$textMatches: empty or SearchResultSet object
-'SpecialSearchNoResults': Called before search result display when there are no
-matches.
-$term: string of search term
-
'SpecialStatsAddExtra': Add extra statistic at the end of Special:Statistics.
&$extraStats: Array to save the new stats
( $extraStats['<name of statistic>'] => <value>; )