This property is used to provide a language code for internationalising pages (being a Text).
See Template:Language how to get multi-language versions of a page
The values should be standard abbreviations for languages, such as "en", "de" or "Zh-tw". Pages without such a code are usually English.
de=German en=English es=Spanish fr=French ja=Japanese nl=Dutch ru=Russian zh-hans=Chinese uk=Ucraine