The various ways to invoke Helpview are:
dthelpview -helpVolume volume [ -locationId id ]
dthelpview -manPage man
dthelpview -file filename
Specifies the name of the volume.sdl file you want to view. A path name is not required unless the volume is not in the current directory and the volume has not been registered.
Specifies an ID. dthelpview displays the topic that contains id. If you do not specify an ID, Helpview uses _hometopic by default.
Displays a dialog that prompts for a man page to view, then displays the requested man page.
Specifies that a particular man page be displayed.
Specifies that a particular text file be displayed.
The default volume and id can be set in dthelpview's app-defaults file, /usr/dt/app-defaults/C/Dthelpview.