@xml:lang Language

The language of the intellectual content of the element for which this is an attribute.

The value of this attribute must conform to IETF RFC 5646 (http://tools.ietf.org/html/rfc5646). For most uses, a primary-language subtag such as “fr” (French), “en” (English), “de” (German), or “zh” (Chinese) is sufficient. These values are NOT case sensitive, but current best practice uses all lower case. In addition to the primary language subtag, the value of this attribute may contain other subtags as well. Values for the various subtags (which can be used in certain combinations) can be obtained from the IANA Language Subtag Registry: http://www.iana.org/assignments/language-subtag-registry.