package Mod;
require Exporter;

BEGIN {
  use vars qw(@ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
  %EXPORT_TAGS = (all => [qw(Foo Bar)]);
  @ISA = qw(Exporter);
  Exporter::export_ok_tags('all');
}
##</code><code>##

use Mod qw(:all);
Foo()

##</code><code>##

package Mod::Sub
use Mod qw(:all);
Foo()