$re = '/^([A-ZäÄÖÜ]{1,3})\-[ ]{0,1}([A-Z]{0,2})[ ]{0,1}([0-9]{1,4}[HE]{0,1})[ ]{0,1}([0-9]{0,2})[ ]{0,1}([0-9]{0,2})$/m';
$str = 'ABC-DE 1234
ABC-DE 1234H
ABC-DE 1234E
ABC-DE 1234 04 10';
preg_match_all($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