key-table-id
    OpenVMS usage:identifier
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference
    Identifies the key definition table for which the DEFINE/KEY
    command is to be performed. The key-table-id argument is the
    address of an unsigned longword that contains the key table
    identifier.
    The key table identifier is returned by SMG$CREATE_KEY_TABLE.
 command-string
    OpenVMS usage:char_string
    type:         character string
    access:       read only
    mechanism:    by descriptor
    String containing the DEFINE/KEY command to be performed. The
    command-string argument is the address of a descriptor pointing
    to the command to be performed.
    The valid qualifiers for the DEFINE/KEY command are as follows:
    o  /TERMINATE
    o  /NOECHO
    o  /LOCK
    o  /IF_STATE
    o  /SET_STATE
    The following two restrictions apply to the DEFINE/KEY
    qualifiers:
    o  If you use the /LOCK qualifier, you must also use the /SET_
       STATE qualifier.
    o  If you use both the /SET_STATE and /TERMINATE qualifiers, you
       may not use /LOCK.