c:\@Work\Perl\monks>perl -le
"use warnings;
 use strict;
 ;;
 package P;
 ;;
 $P::A = 'something';
 ;;
 package main;
 ;;
 my $A = 123;
 $::A = 456;
 ;;
 print 'package ', __PACKAGE__;
 print qq{\$A is $A};
 print qq{\$::A is $::A};
 print qq{\$main::A is $main::A};
 print qq{\$P::A is $P::A};
 print qq{\n};
 ;;
 our $A;
 print 'package ', __PACKAGE__;
 print qq{\$A is $A};
 print qq{\$::A is $::A};
 print qq{\$main::A is $main::A};
 print qq{\$P::A is $P::A};
"
"our" variable $A masks earlier declaration in same scope at -e line 1.
package main
$A is 123
$::A is 456
$main::A is 456
$P::A is something

package main
$A is 456
$::A is 456
$main::A is 456
$P::A is something