Description

   The DIFFERENCES/CLASS command compares the contents of two
   classes. If CMS finds differences, it creates a file named
   first-class-name.DIF in your current default directory (unless
   /OUTPUT is in effect.) If the contents of the classes are the
   same, it issues a message to that effect and does not create a
   differences file.

   Note: Both classes must reside in the same library of the search
   list or an error will occur.  

   A difference is defined as one of the following:

   o  A particular generation of an element is a member of one
      class but no generation of the element is a member of the
      other class.

   o  One particular generation of an element is a member of one
      class and a different generation of the same element is a
      member of the other class.

   Only the generations that differ are displayed in the differences
   file (unless you specify /FULL).

   A heading at the beginning of the differences file includes the
   name of the user that issued the command, the date and time the
   command was issued, and the class names of the two classes being
   compared.