$re = '/(?i)
^
(?=.{1,30}$)
(?:
[a-z.,\'\-\h]{2}%
|
[a-z.,\'\-\h]
)+
$/mx';
$str = 'asdSRVGD
as%
assvd-,\'
asdbSERF,%
### Incorrect %
a%
%
### Length >= 30
abcdefghijklmnopqrstuvwxyzABCDE
### Invalid characters
1abcd';
preg_match_all($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