$re = '/\bPAR1234\b|\bPAR\b.*\b1234\b/';
$str = 'PAR1234
PAR 1234
PAR 5678, 1234
PAR 9991234999, 1234
PAR !@#-= 1234
PAR1234-122
PAR#1234-233
ANY TEXT PAR#1234-233
PART 1234
APART 1234
PAR 1234999
PAR 9991234
PAR 9991234999
1234 PAR ';
preg_match_all($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