This part of ISO/IEC 14776 defines a Reduced Block Command set for logical block devices. The Reduced Block Commands along with the required SPC-2 commands and their restrictions described in this standard, fully specify the complete command set for RBC logical block devices. The purpose of this part of ISO/IEC 14776 is to provide a command set of reduced requirements and options from SCSI Block Commands (SBC) (ISO/IEC 14776-321) for block devices. The reduced command set is intended to more closely match the functionality required for simple block logical units. The specified commands place no restrictions on device performance. The initial focus of this command set was to enable rigid disks and removable media devices attached to Serial Bus and utilizing SBP-2 (ISO/IEC 14776-232) for command and control.