poletti@PolettiX:~/sviluppo/perl$ nl mikasue.pl
     1  #!/usr/bin/perl
     2  use strict;
     3  use warnings;
     4  { # scope reduction
     5  our $MW = "Hello, mikasue!";
     6  print "\$MW is '$MW'\n";
     7  print "Current package is ", __PACKAGE__, "\n";
     8  print "\$main::MW is '$main::MW'\n";
     9  } # end of "our" scope
    10  package Whatever;
    11  no strict;  # note: no strict here!
    12  print "\$MW is '$MW'\n";
    13  print "Current package is ", __PACKAGE__, "\n";
    14  print "\$main::MW is '$main::MW'\n";

poletti@PolettiX:~/sviluppo/perl$ perl mikasue.pl
Name "Whatever::MW" used only once: possible typo at mikasue.pl line 12.
$MW is 'Hello, mikasue!'
Current package is main
$main::MW is 'Hello, mikasue!'
Use of uninitialized value in concatenation (.) or string at mikasue.pl line 12.$MW is ''
Current package is Whatever
$main::MW is 'Hello, mikasue!'