The REPOSITORY OPERATOR command invokes the CDO utility.  CDO is an
  interactive utility that allows you to define and manage CDO
  repositories, define data definitions, perform pieces tracking, and
  verify and fix repositories.  For more information about CDO, type:

    $ REPOSITORY OPERATOR

    At the CDO> prompt, type HELP.

  See also DICTIONARY OPERATOR; the DICTIONARY OPERATOR and the
  REPOSITORY OPERATOR commands perform the same function.  Each command
  can be used to invoke the CDO utility.