The xml:lang value will be inherited from the immediately enclosing element, or from its parent, and so on up the document hierarchy. It is generally good practice to specify xml:lang at the highest appropriate level, noticing that a different default may be needed for the <teiHeader> from that needed for the associated resource element or elements, and that a single TEI document may contain texts in many languages. Only attributes with free text values (rare in these guidelines) will be in the scope of xml:lang. The authoritative list of registered language subtags is maintained by IANA and is available at https://www.iana.org/assignments/language-subtag-registry. For a good general overview of the construction of language tags, see https://www.w3.org/International/articles/language-tags/, and for a practical step-by-step guide, see https://www.w3.org/International/questions/qa-choosing-language-tags.en.php. The value used must conform with 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. |