Click to Enlarge. So close.
The credit card remote control is shown here. Octava obviously uses this remote with other devices as well, as it has several buttons that are not used with the HDMX42.
At the top of the remote there are four letter buttons, A-D. A and B are the buttons for selecting outputs. The C and D buttons are not used. Also at the top are a + button and a - button. Those can be used to toggle between adjacent input sources.
Tthose buttons, are buttons numbered 1 - 5 and a * button. Once again, not all are used, only 1 through 4.
At the bottom is the Off/On switch, and Aux button (not used, best I can tell), and the LED light (off/on) control.