Language code

A 2-character (ISO 639-1) or 3-character (ISO 639-2 and following) code used to indicate the language of a document or passage of text. The language code is made up of two parts separated by a hyphen on the lang="[code]-[option]" model.

• [code] represents a valid language code of 2 or 3 characters;
• [option] is an indication left to the author's discretion.

When a country code is used as an option, it can be used to indicate a regionalisation of the language, e.g. "en-us" indicates American English. The language code indication only concerns the [code] part before the hyphen.