1 - Does NOT output song / artist / etc on the serial port.
2 - Puts song/artist/etc on the serial port.

That's not what I see in there. In the developer info section of the RioCar site, it seems to me that it says:

notify=x
(where x is...)
0. does not output song / artist / etc. on the serial port.
1. puts song / artist / genre / etc. on the serial port.

Seems pretty clear to me? Don't know where the confusion lies?

(Disclaimer: I don't maintain that section of the site.)