$re = '/(?:^([A-Y])?\s*(\d{0,4})\s?([a-d])?)|(?:^((?:\w+)|(?:\w+,)|(?:\w+, \w*))?\s*((?:&{1,2}|and|or|\|{2})\s+(?:.*)*)*)
/m';
$str = 'thra
^\\s*((?:\\w+)(?:,?\\s?)(?:,\\s\\w+\\s*)*)
^\\s*?((?:\\w+){1}\\s*(?:(?:,?)|(?:,\\s\\w+))*\\s*)
\\s*((?:&{1,2}|and|or|\\|{2})\\s+(?:.*)*)*
(?:^([A-Y] +)*(\\d{0,4}) ?(a-d))|';
preg_match_all($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