This document is a NOTE made available by the W3 Consortium for discussion only. In HTML elements, the lang attribute specifies the natural language. Overview Most of the existing documents are monolingual. This is indeed the most sensible approach.
Some documents are bilingual and few are trilingual or n-lingual.
A common practice is to have one small document that is a menu of languages. Immediately, the server will send an appropriate document. Je suis un Berlinois . These language codes are the same used in the lang attribute of some HTML elements. The order of the languages in the Content-Language is significant.