The doc comments for _open_temp_view put it in "file functions" and miscellaneous categories, _create_temp_view is in miscellaneous and _delete_temp_view is in the "selection functions" category. I suspect the last two should be in the file functions category as well.
The help for _delete_temp_view says the wid passed to it should have come from a call to _create_temp-view - but it could also have come a call to open_temp_view. The help for open and create should explain that you have to call _delete_temp_view when you're finished with the buffer and that you should also normally restore the window as well, using activate_window.