my $name = qr/(\w[\w-]*\w?)/;      # any valid hostname segment
my $nnam = qr/(($name\.)*$name)/;  # one or more "name" segments

my @domainnames = (
  { re => qr/$nname\.com/, desc => 'a commercial domain'        },
  { re => qr/$nname\.edu/, desc => 'an educational institution' },
);