code: static void register() {
          Transliterator.registerFactory("Any-NFC", new Transliterator.Factory() {
              @Override
              public Transliterator getInstance(String ID) {
                  return new NormalizationTransliterator("NFC", Normalizer2.getNFCInstance());
              }
          });
          Transliterator.registerFactory("Any-NFD", new Transliterator.Factory() {
              @Override
              public Transliterator getInstance(String ID) {
                  return new NormalizationTransliterator("NFD", Normalizer2.getNFDInstance());
              }
          });
          Transliterator.registerFactory("Any-NFKC", new Transliterator.Factory() {
              @Override
              public Transliterator getInstance(String ID) {
                  return new NormalizationTransliterator("NFKC", Normalizer2.getNFKCInstance());
              }
          });
          Transliterator.registerFactory("Any-NFKD", new Transliterator.Factory() {
              @Override
              public Transliterator getInstance(String ID) {
                  return new NormalizationTransliterator("NFKD", Normalizer2.getNFKDInstance());
              }
          });
          Transliterator.registerFactory("Any-FCD", new Transliterator.Factory() {
              @Override
              public Transliterator getInstance(String ID) {
                  return new NormalizationTransliterator("FCD", Norm2AllModes.getFCDNormalizer2());
              }
          });
          Transliterator.registerFactory("Any-FCC", new Transliterator.Factory() {
              @Override
              public Transliterator getInstance(String ID) {
                  return new NormalizationTransliterator("FCC", Norm2AllModes.getNFCInstance().fcc);
              }
          });
          Transliterator.registerSpecialInverse("NFC", "NFD", true);
          Transliterator.registerSpecialInverse("NFKC", "NFKD", true);
          Transliterator.registerSpecialInverse("FCC", "NFD", false);
          Transliterator.registerSpecialInverse("FCD", "FCD", false);
      }
docs: System registration hook.