Property:Language code
From semantic-mediawiki.org
"Language code" is a predefined property that represents a BCP47 formatted language code and is provided by Semantic MediaWiki. This property is pre-deployed (also known as special property) and comes with additional administrative privileges but can be used just like any other user-defined property.
This property is used to provide a language code for internationalising pages (being a String). The values should be standard abbreviations for languages, such as "en", "de" or "Zh-tw". Pages without such a code are usually English.
