$re = '/^([A-Za-z0-9]{2})([0-9]{2})((?:[A-R][0-9]{2}){0,10})((?:[0-9]{4}){0,12})((?:[A-Z])?)$/m';
$str = '0101110112011301210122012301310132013301410142014301B
0101B
0101B12B
01011011B
0101B121111B
010110111011B
0101B1210111011B
0520D01D53D
0620E01E53D
0724
0803E23J54B
0903
1006E25J56B
1103B01
1407
1504
1807E30J61B
1904K24R
2003K41M54R
2104K06R
2203H37M68B
72B6P271531
05BRE010941';
preg_match_all($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