The 
                  description element is the root container element for a description. It consists of an optional container element for metadata information
                  (the 
                  
                     head
                     ) and a required container for the different description types and alternate image renditions (the 
                  
                     body
                     ).
                  
               
The language of the description can be specified by attaching an 
                  
                     xml:lang
                      attribute to the 
                  description element. If the description will be made available in a standalone context (i.e., in which its language cannot be inherited
                  from a host content document), the language should always be specified.
                  
               
The 
                  DIAGRAM Description profile provides the ability to compile one or more 
                  description elements into a single document for distribution (e.g., to accompany an EPUB).
                  
               
When storing a description in a standalone context, the Description feature namespace 
                  http://www.daisy.org/ns/z3998/authoring/features/description/ should be declared on the 
                  description element using the xmlns namespace association mechanism defined in 
                  
                     XMLNAMES
                     . Although not required, the prefix 
                  d is recommended.