(identifier) provides a unique identifier for the element bearing the attribute. (language) indicates the language of the element content using a tag generated according to BCP 47 provides a base URI reference with which applications can resolve relative URI references into absolute URI references. signals an intention about how white space should be managed by applications. the processor should treat white space according to the default XML white space handling rules the processor should preserve unchanged any and all white space in the source Indicates the language of the element content. The allowed values are found in IETF RFC 4646 or its successor. This attribute is optional for elements that use this attribute class. For a description, see the information at the martif element. Indicates the language of the language section. This attribute is required for the langSet element. See also the description on the martif element.