CDO (Common Dictionary Operator) is an interactive utility that allows
  you to define and manage CDO dictionaries, define data definitions,
  perform pieces tracking, and verify and fix dictionaries.

  In the CDO environment, you can accomplish all the data description,
  administration, and dictionary management functions.  In addition, a
  flexible menu-driven editor allows you to easily create and modify
  field and record definitions.  For more information about CDO, type:

   $ REPOSITORY OPERATOR

  Then, from the CDO> prompt, type HELP to display information on
  specific CDO commands.