$re = '/(\d+)x(\d+)|-\s*([\w\s]+)|(\w+)/m';
$str = '21x04 - Some Text (04)
6x03 - Some Text (00 - Some Text)
6x03 - Some Text (00 - Some Text) (Some Text)
23x01 - Some Text (10) - Some Text (02)';
preg_match_all($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