It's the simple feature of saving the receiver's settings across a power loss.

That's why the Rio Receiver is supposed to send "State!" packets to the server every now and then. When it boots, it's supposed to send a "State?" packet to the server to retrieve its state. I don't recall whether everything that you want to store would have been passed in those packets, though.

As I recall, we didn't get around to actually implementing it, and the "third party OEM" weren't that bothered about it.