Use @samp{-} as @var{output-file} to write output to standard output.
-If no @option{-o} option is used, then @pspp{} writes output to standard
-output in plain text format.
+If no @option{-o} option is used, then @pspp{} writes text and CSV
+output to standard output and other kinds of output to whose name is
+based on the format, e.g.@: @file{pspp.pdf} for PDF output.
@item @option{-O @var{option}=@var{value}}
Sets an option for the output file configured by a preceding