$re = '/^(?:\d{1,4}[A-Za-z]|\/?\d{1,4})/m';
$str = 'Streets numbers:
/1
78
3a
89/
-1 (special case)
1
Apartment:
1-
2-5
12
7a
3a
Aadresses for testing:
Põllu tn 3-1-
Joa tn 3a-1-3
Kapa vkt 78
Kivimäe/1
Aia tn 11/2-5
Männiku tee 89/1-438, Nõmme linnaosa, Tallinn, Harju maakond
Männiku pst
Männiku mnt 12345
1. Mai tn
';
preg_match_all($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