The RESERVE command sends a copy of the specified generation of
    each specified element to your current default directory (or to
    another location if you specified the /OUTPUT qualifier). Each
    element is marked as reserved. Usually, after you have modified
    the file, you return your changes to the library with the REPLACE
    command. Alternatively, you can cancel the reservation with the
    UNRESERVE command.

    You can reserve more than one generation of the same element if
    concurrent reservations are allowed.  If a generation of an
    element is reserved by you or another user, or a
    generation of the element is under review or has been rejected,
    CMS displays the current reservations and review comments, and
    prompts whether you want to proceed with the command. If you
    type YES, you are added to the list of current reservers. The
    transaction is recorded as an unusual occurrence.
    If you type NO or press RETURN, no action is taken.

    If a version of the output file exists in your default directory
    when you issue the RESERVE command, CMS notifies you. A new
    version is then created with the next higher version number.

    When you retrieve a generation of an element from a CMS library,
    CMS restores the file creation and revision times. The file that
    is placed in your directory has the same creation and revision
    times as the file that was used to create the generation that
    you are reserving. If you specify /MERGE, the file placed in your
    default directory has the current creation and revision times.