This part of ISO/IEC 14776 defines the SCSI commands that are mandatory and options for all SCSI devices. It also defines the SCSI commands that may apply to any device model. Since a host processor is a part of any SCSI domain, the processor device model is defined in this standard. The commands that may be implemented by a SCSI processor device are also define in this standard. Some target SCSI devices may implement an initiator subset of the processor device model to support the Asynchronous Event Reporting capability defined in the SCSI-3 Architecture Model.