本标准定义了命令集扩展，以便于顺序访问设备类型的操作 SCSI流设备类的成员。本标准的条款与适用的 SCSI主命令-3标准的条款中，完全指定了 SCSI流设备类的顺序访问设备类型成员。本标准的目标是提供以下内容:a）允许应用程序客户端通过SCSI服务提供子系统与一个逻辑单元进行通信，该逻辑单元在查询命令响应数据的设备类型字段中声明自己是顺序访问设备；b） 定义顺序访问设备类型特有的命令；andc）定义用于管理顺序访问设备类型操作的命令。

This standard defines the command set extensions to facilitate operation of the sequential-access device type member of the SCSI stream device class. The clauses of this standard, implemented in conjunction with the applicable clauses of the SCSI Primary Commands - 3 standard, fully specify the standard command set for the sequential-access device type member of the SCSI stream device class.The objectives of this standard are to provide the following:a) permit an application client to communicate over a SCSI service delivery subsystem, with a logical unit that declares itself to be a sequential-access device in the device type field of the INQUIRY command response data;b) define commands unique to the sequential-access device type; andc) define commands to manage the operation of the sequential-access device type.