On Ubuntu 16.04, the Logitech R400's blackout button gets mapped to 'v' (keyCode 86). I don't know why this is, but since nothing else is currently using 'v', this allows it to be supported out of the box.
On Ubuntu 16.04, the Logitech R400's blackout button gets mapped to 'v' (keyCode 86). I don't know why this is, but since nothing else is currently using 'v', this allows it to be supported out of the box.