$re = '/(?<!\d)(?=[\d. -]{11}(?!\d))\d{1,}([. -])\d{1,}\1\d{1,}(?!\d)/m';
$str = '222-33-4444
333.77-8888
111 77.9998
111 22 3333
11-222222-9
a222-33-4444
222-33-4444b
';
preg_match_all($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