Here is the code of USB descriptors (device descriptor as an example). I understand those settings except the BCD device release number. I read USB codes for several different projects. Their device release number are all different. What decides the device release number? is there a list?
const unsigned char usb_dev_desc[] = {
18,
0x01, // device descriptor
0x00, 0x02, // USB 2.0
0x02, // Class CDC
0x00, // subclass
0x00, // protocol
0x08, // max packet size
0xd8, 0x04, // VID
0x0a, 0x00, // PID
0x00, 0x01, // device release number ????
0x01, // manuf string
0x02, // product string
0x00, // serial number string
0x01 // no. of configurations
};
I think the producer of the device decides what number this device should have.