You probably wouldn't guess what this does from the name alone, but it
actually selects a range of tracks to play. It's slightly different than
using --start because it confines the range to just that track and you
cannot seek before it. The functionality is useful, but you can
accomplish exactly the same thing with --start and --end. Also the
implementation of the cdda option is weird because starting from a track
after 1 makes it impossible to seek before it. There's no reason to have
this when using the core option is simply better and works fine.