Syntax:

      /SUBDICTIONARY = file-specification
      /NOSUBDICTIONARY

  Use /SUBDICTIONARY to create a  subdictionary.   Subdictionary  files
  allow  you  to  store portions of the dictionary on different devices
  and to augment CDD protection with VMS file security mechanisms.  The
  file specification is a standard VMS file specification, and you must
  include device and directory names for this file.  The  default  file
  name  is  CDD.DIC.   You can use a system logical name as any part of
  the subdictionary file specification.  You  cannot  use  a  group  or
  process logical name.

  Use /NOSUBDICTIONARY to create a dictionary  directory  in  the  main
  dictionary file.  /NOSUBDICTIONARY is the default.