Must a USB storage device contain a unique serial number?
Yes. To comply with the USB Mass Storage Class Bulk-Only Transport Specification, all USB storage devices must contain a unique (12 digits or longer) serial number, represented as a UNICODE string. Refer to section 4.1.1 of the USB Mass Storage Class (Bulk-Only Transport) specification and note that serial number characters must be 0x0030-0x0039 or 0x0041-0x0046.