let options = [
"-", Arg.Unit (fun () -> remaining := "-" :: !remaining),
"\t\tadd standard input as source of a todo list to read" ;
"--rss", Arg.Unit (fun () -> output_type := Rss), "\toutput RSS (default)";
"--max-items", Arg.Int (fun n -> add_filter (Rss.keep_n_items n)),
"n\n\t\tkeep only n items in each input channel";
]