Volume serial number (VSN)

The 32-bit serial written into a volume's boot sector when it is formatted, shown as XXXX-XXXX and stored in shortcuts and Jump Lists.

Formatting a volume writes a new serial into its boot record: offset 0x43 on FAT32, 0x27 on FAT12/16, 0x64 on exFAT, 0x48 on NTFS. Windows prints it as 3C9D-51A2.

Shortcuts and Jump Lists record the VSN of the volume their target was on, and Partition/Diagnostic 1006 logs the boot record it comes from — which ties a file to a physical device. Two VSNs for one device mean it was reformatted. See Partition/Diagnostic 1006.