Lists and explains LATCP commands. If  you do not specify a command name,
  HELP displays  general information on the commands for which help is
  available. You can supply a command name or press RETURN. Supplying a
  command name obtains more detailed information on that command. If you
  respond with RETURN, the HELP command exits.

  Format:

    HELP [command_name]

Additional information available:

command name

  Name of a LATCP command.