xml:lang 

Attempting to install the relevant ISO 2- and 3-letter
codes as the enumerated possible values is probably never
going to be a realistic possibility.  See
RFC 3066 at http://www.ietf.org/rfc/rfc3066.txt and the IANA registry
at http://www.iana.org/assignments/lang-tag-apps.htm for
further information.

Attribute Information

Used By

Complex Types mpeg7:PersonNameType, mpeg7:PlaceType, mpeg7:TextualBaseType, tva:ClassificationSchemeTableType, tva:CreditsInformationTableType, tva:GroupInformationTableType, tva:GroupInformationType, tva:MetadataOriginationInformationTableType, tva:OnDemandProgramType, tva:OnDemandServiceType, tva:ProgramInformationTableType, tva:ProgramInformationType, tva:ProgramLocationTableType, tva:ProgramReviewTableType, tva:PurchaseInformationTableType, tva:PushDownloadType, tva:ReviewType, tva:RightsInformationTableType, tva:ScheduleEventType, tva:ScheduleType, tva:SegmentGroupInformationType, tva:SegmentInformationTableType, tva:SegmentInformationType, tva:ServiceInformationTableType, tva:ServiceInformationType, tva:TVAClassificationSchemeType, tva:TVAMainType
Elements mpeg7:PlaceType/mpeg7:PostalAddress, tva:RightsStatementType/tva:RightsLink
Attribute Group xml:specialAttrs

Source 

<xs:attribute name="lang" type="xs:language">
  <xs:annotation>
    <xs:documentation>Attempting to install the relevant ISO 2- and 3-letter codes as the enumerated possible values is probably never going to be a realistic possibility. See RFC 3066 at http://www.ietf.org/rfc/rfc3066.txt and the IANA registry at http://www.iana.org/assignments/lang-tag-apps.htm for further information.</xs:documentation>
  </xs:annotation>
</xs:attribute>

Sample