&$text : text of the new section
Return false and put the merged text into $text to override the default behavior.
+'PreferencesGetLegend': Override the text used for the <legend> of a preferences section
+$key: the section name
+&$legend: the legend text. Defaults to wfMsg( "prefs-$key" ) but may be overridden
+
'PrefixSearchBackend': Override the title prefix search used for OpenSearch and
AJAX search suggestions. Put results into &$results outparam and return false.
$ns : array of int namespace keys to search in