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";
"--tdl", Arg.Unit (fun () -> output_type := Tdl), "\toutput a new todo list (default)\n\t\t(used to merge todo lists)";
"--filter", Arg.String (fun s -> filter := Some (Tdl.filter_of_string s)),
"s\tapply the given filter on read groups";
"--split-by-day", Arg.String (fun s -> output_type := Tdl_by_day s),
"<prefix>\n\t\tsplit todo list(s) to create one separate todo list by day,\n"^
"\t\tin files named prefix-<year>-<month>-<day>.tdl";
]