/sys$common/syshlp/helplib.hlb CMS, RESERVE, Qualifiers, /CONFIRM  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Controls whether CMS prompts you for confirmation before each
    transaction.

    When you specify /CONFIRM and run CMS in interactive mode, CMS
    prompts you for confirmation. If you type YES, ALL, TRUE, or 1,
    CMS executes the transaction.  If you type NO, QUIT, FALSE, 0,
    or press RETURN or CTRL/Z, no action is performed. If you type
    any other character, CMS continues to prompt until you type an
    acceptable response.

    CMS does not prompt for confirmation in batch mode.

    You cannot use /NOCONFIRM to override the prompt generated when
    you attempt to reserve a generation of an element that is already
    reserved by you or by another user.