Command mode allows subcommands to be issued as verbs instead of
   as command qualifiers.

   As shipped, command mode is the default mode used during KeyCapture
   interactive command prompting, and non-command mode is used for
   single-line DCL KeyCapture commands.

   As shipped:

     In single-line DCL commands, subcommands are qualifiers:

       $ KCAP /TRACK           ! Start KeyCapture for the current terminal.
       $ KCAP /SHOW VERSION    ! Show the version of KeyCapture.

     During interactive command-prompting, subcommands are verbs:

       $ KCAP                  ! Enter command-prompting mode.
       KCAP> TRACK             ! Start KeyCapture for the current terminal.
       KCAP> SHOW VERSION      ! Show version of KeyCapture.
       KCAP> SPAWN             ! Spawn a subprocess.

   The subcommands which are accepted as verbs in command mode are:

   ATTACH, EXIT, FORMAT, HELP, LICENSE, NODE_NAME_CHANGE, NOTRACK, QUIT,
   SHOW, SHUTDOWN, SPAWN and TRACK.

   The qualifier form of all the above subcommands is also still accepted
   when in command mode, e.g. "KCAP> /TRACK" is accepted.