The serial number of the audio device (soundcard or virtual audio cable VAC) is generated from part of the active MAC address of the computer network interface and a counter.
W-CODE recognizes sound devices in the computer as its input devices. The serial number of a sound device comes from the built-in network card of the computer. The serial number is used as a reference for custom inputs ans default settings. You will lose some settings if you switch to a different LAN adaptor, e.g., switching from a LAN to a WLAN connection.
WAVECOM hardware W74PC, W-PCI and W-PCIe are detected by their corresponding application, they are also listed in the Device dialog window with the device name and serial number. The serial number is used as a reference for custom inputs and default settings. It is from the decoder hardware and will never change.
W-CODE Device dialog window.