(Non-normative) The DITA 1.1 specification was designed to be backwards-compatible with
    applications that conform to the DITA 1.0 specification.
    The following major changes to the architecture provided added functionality for DITA 1.1:
        - A <bookmap> specialization for encoding book-specific information in a DITA map
 
        - A <glossentry> specialization for glossary entries
 
        - Indexing specializations for see, see-also, page ranges, and sort order
 
        - Improvements to graphic scaling capability
 
        - Improved short description flexibility through a new <abstract> element
 
        - Specialization support for new global attributes, such as conditional processing
          attributes
 
        - Support for integration of existing content structures through the <foreign>
          element
 
        - Support for new kinds of information and structures through the <data> and
          <unknown> elements
 
        - Formalization of conditional processing profiles