use vars qw($sku, $description, $price, $qty);

foreach my $item (@items) {
    local($sku, $description, $price, $qty) = @$item;
    write(PURCHASEORDER);
}

##</code><code>##

use strict;

format STDOUT =
@<<<<<<<  
$::foo
.

local $::foo = 'a string';
write STDOUT;

__output__

a string