$re = '/^(?!.*(?:\bId="\d+"\b|\b4[78][0-9]{14}\b)).*?(\bhello\b|\b49[0-9]{14}\b)/m';
$str = 'Id="4912345678912345"
Id="4712345678912345"
4712345678912345
4912345678912345';
preg_match_all($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