it could just be using the vid/pid of the keyboard Yes, and if so, is there a list somewhere, and can it be augmented? why make it emulate a keyboard? The background of this is that it's HID support in CircuitPython, which runs on a variety of microcontrollers. There are many projects that want to emulate a keyboard, mouse, or other HID device, attached to a number of host OS's. It can be used to build a "real" keyboard as well. So we'd like to identify these devices as regular HID devices, not vendor-defined devices.