$re = '/\{\{\s*(d(ab|isamb(ig(uation)?)?)|(((geo|hn|road?|school|number)dis)|[234][lc][acw]|(road|ship)index))\s*(\|[^}]*)?\}\}|is a .*disambiguation.*page/m';
$str = '';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php