$re = '/^(?:[\w:\-() ]+)$/m';
$str = 'Description: Corsican
Description: Cree
Description: Czech
Description: Church Slavic
Description: Church Slavonic
Description: Old Bulgarian
Description: Old Church Slavonic
Description: Old Slavonic
Description: Chuvash
Description: Welsh
Description: Danish
Description: German
Description: Dhivehi
Description: Divehi
Description: Maldivian
Description: Dzongkha
Description: Ewe
Description: Modern Greek (1453-)
Description: English
Description: Esperanto
Description: Spanish
Description: Castilian
Description: Estonian
Description: Basque
Description: Persian';
$subst = "";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
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