$re = '/\d(?! )\w*.\d(?! )\w*.\d(?! )\w*.\d(?! )\w*/';
$str = '100371 (Choice Classification) Infants/Girls Woven Short, Cotton 100371 (Single Classification) 6209.20.00.90 Infants More...
100371 (Single Classification) 6204.62.90.90 Girls More...';
preg_match_all($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