sub validate {
-    my ($number) = @_;
+    my ($number, $param) = @_;
     my ($i, $sum, $weight);
    
     return 0 if $number =~ /[^\d\s]/;

     $number =~ s/\D//g;

     return 0 unless length($number) >= 9 && 0+$number;
+    return 0 unless length($number) >= 13 && !(defined $par am->{ISOstrict} && $param->{ISOstrict});

     for ($i = 0; $i < length($number) - 1; $i++) {
 	 $weight = substr($number, -1 * ($i + 2), 1) * (2 - ($i % 2));
	 $sum += (($weight < 10) ? $weight : ($weight - 9));
     }

     return 1 if substr($number, -1) == (10 - $sum % 10) % 10;
     return 0;
 }