if (decoded != normalizeNfc(decoded)) return null

  // TODO: Must not begin with a combining mark.
  // TODO: Each character must be 'valid' or 'deviation'. Not mapped.
  // TODO: CheckJoiners from IDNA 2008
  // TODO: CheckBidi from IDNA 2008, RFC 5893, Section 2.

  return Punycode.encode(decoded)

          "gov.ck",
          "org.ck",
          "org.mK",
          "us",
          // keep-sorted end
          "j\u00f8rpeland.no", // "jorpeland.no" (first o slashed)
          "xn--jrpeland-54a.no" // IDNA (punycode) encoding of above
          );

  private static final ImmutableSet<String> PS_NOT_RS = ImmutableSet.of("blogspot.com", "uk.com");

  private static final ImmutableSet<String> PS =

          "gov.ck",
          "org.ck",
          "org.mK",
          "us",
          // keep-sorted end
          "j\u00f8rpeland.no", // "jorpeland.no" (first o slashed)
          "xn--jrpeland-54a.no" // IDNA (punycode) encoding of above
          );

  private static final ImmutableSet<String> PS_NOT_RS = ImmutableSet.of("blogspot.com", "uk.com");

  private static final ImmutableSet<String> PS =

 * names</a> such as {@code 网络.cn} are supported, as are the equivalent <a
 * href="http://en.wikipedia.org/wiki/Internationalized_domain_name">IDNA Punycode-encoded</a>
 * versions.
 *
 * @author Catherine Berry
 * @since 5.0
 */
@GwtCompatible
@Immutable
public final class InternetDomainName {

    returned.

 *  Upgrade: [Okio 3.9.0][okio_3_9_0].

 *  Upgrade: [Kotlin 1.9.23][kotlin_1_9_23].

 *  Upgrade: [Unicode® IDNA 15.1.0][idna_15_1_0]


## Version 5.0.0-alpha.12

_2023-12-17_

We took too long to cut this release and there's a lot of changes in it. We've been busy.