the value consists of a single token which may however contain punctuation characters, whitespace or word separating characters. It need not be restricted to numbers.
The value must conform to BCP 47. If the value is a private use code (i.e., starts with x- or contains -x-), a language element with a matching value for its ident attribute should be supplied in the TEI header to document this value. Such documentation may also optionally be supplied for non-private-use codes, though these must remain consistent with their (IETF)Internet Engineering Task Force definitions.
<p> … The consequences of this rapid depopulation were the loss of the last <foreign xml:lang="rap">ariki</foreign> or chief (Routledge 1920:205,210) and their connections to ancestral territorial organization.</p>