VAX Common Data Dictionary Data Definition Language  (CDDL)  contains
  statements  and  clauses  you  use  in  a source file.  When you have
  created and debugged the CDDL source file, you store it  in  the  CDD
  using the CDDL compiler.  CDDL contains:

   o  DEFINE and END statements, which define CDD records

   o  Field  description  statements,  which   describe   the   general
      structure of records

   o  Field attribute clauses, which describe characteristics of fields
      within CDD records