#define USB_SC_RBC      0x01            // Reduced Block Commands (flash)
#define USB_SC_8020     0x02            // SFF-8020i, MMC-2, ATAPI (CD-ROM)
#define USB_SC_QIC      0x03            // QIC-157 (tape)
#define USB_SC_UFI      0x04            // UFI (floppy)
#define USB_SC_8070     0x05            // SFF-8070i (removable)
#define USB_SC_SCSI     0x06            // Transparent SCSI