The USB spec requires that USB devices be connected-device agnostistic. That is, they must be capable of communicating with any device, over USB, that knows th

The USB spec requires that USB devices be connected-device agnostistic. That is, they must be capable of communicating with any device, over USB, that knows the proper codes/bytes/etc. Hiding the codes/keeping them secret, like most vendors do, is okay -- the USB spec does not require disclosure. BUT changing the codes to prevent interoperability is prohibited by the USB spec b/c it defeats the whole point of the USB spec.