"home.netscape.com",
          "web.MIT.edu",
          "foo.eDu.au",
          "utenti.blah.IT",
          "dominio.com.co");

  private static final ImmutableSet<String> NON_RS =
      ImmutableSet.<String>builder().addAll(NON_PS).addAll(PS_NOT_RS).build();

  private static final ImmutableSet<String> TOP_UNDER_REGISTRY_SUFFIX =
      ImmutableSet.of("google.com", "foo.Co.uk", "foo.ca.us.");