```properties
supported.languages=ar,bg,bn,ca,ckb_IQ,cs,da,de,el,en_IE,en,es,et,eu,fa,fi,fr,gl,gu,he,hi,hr,hu,hy,id,it,ja,ko,lt,lv,mk,ml,nl,no,pa,pl,pt_BR,pt,ro,ru,si,sq,sv,ta,te,th,tl,tr,uk,ur,vi,zh_CN,zh_TW,zh
```

**Optional configurations:**

If you create online help documentation:
```properties
online.help.supported.langs=ja,sv  # Add your language
```

If you have forum support:
```properties

        value = "zh";
        assertEquals("zh", systemHelper.normalizeLang(value));

        value = "zh-cn";
        assertEquals("zh_CN", systemHelper.normalizeLang(value));

        value = "zh_CN";
        assertEquals("zh_CN", systemHelper.normalizeLang(value));

        value = "zh-tw";
        assertEquals("zh_TW", systemHelper.normalizeLang(value));

        value = "zh_TW";

        assertArrays(new String[] { "ja", "zh-cn" }, fessConfig.normalizeQueryLanguages(new String[] { "ja", "zh" }));
        assertArrays(new String[] { "ja", "zh-cn" }, fessConfig.normalizeQueryLanguages(new String[] { "ja", "zh_CN" }));
        assertArrays(new String[] { "ja", "zh-cn" }, fessConfig.normalizeQueryLanguages(new String[] { "ja", "zh-cn" }));