+.IP
+By issuing the
+.B I-1\en0\en
+command, a client will specify that he is using the VERSION 1 protocol.
+.IP
+For a VERSION 0 client, the
+.I operation
+parameter is the platform
+.B mt_op
+value (could be different if the client and the
+.B rmt
+server are on two different platforms). For a VERSION 1 client, the
+.I operation
+parameter is standardized as below:
+.RS
+.TP
+.B 0
+Issue a
+.B MTWEOF
+command (write
+.I count
+end-of-file records).
+.TP
+.B 1
+Issue a
+.B MTFSF
+command (forward space over
+.I count
+file marks).
+.TP
+.B 2
+Issue a
+.B MTBSF
+command (backward space over
+.I count
+file marks).
+.TP
+.B 3
+Issue a
+.B MTFSR
+command (forward space
+.I count
+inter-record gaps).
+.TP
+.B 4
+Issue a
+.B MTBSR
+command (backward space
+.I count
+inter-record gaps).
+.TP
+.B 5
+Issue a
+.B MTREW
+command (rewind).
+.TP
+.B 6
+Issue a
+.B MTOFFL
+command (rewind and put the drive offline).
+.TP
+.B 7
+Issue a
+.B MTNOP
+command (no operation, set status only).
+.RE
+.TP
+.B i\fIoperation\fR\en\fIcount\fR\en
+Perform an extended
+.B MTIOCOP
+.BR ioctl (2)
+command using the specified parameters. The parameters are interpreted as the
+.B ASCII
+representations of the decimal values to place in the
+.B mt_op
+and
+.B mt_count
+fields of the structure used in the
+.B ioctl
+call. The return value is the
+.I count
+parameter when the operation is successful. The possible operations are:
+.RS
+.TP
+.B 0
+Issue a
+.B MTCACHE
+command (switch cache on).
+.TP
+.B 1
+Issue a
+.B MTNOCACHE
+command (switch cache off).
+.TP
+.B 2
+Issue a
+.B MTRETEN
+command (retension the tape).
+.TP
+.B 3
+Issue a
+.B MTERASE
+command (erase the entire tape).
+.TP
+.B 4
+Issue a
+.B MTEOM
+command (position to end of media).
+.TP
+.B 5
+Issue a
+.B MTNBSF
+command (backward space count files to BOF).
+.RE
+.TP
+.B S
+Return the status of the open device, as obtained with a
+.B MTIOCGET
+.B ioctl
+call. If the operation was successful, an \*(lqack\*(rq is sent with the size
+of the status buffer, then the status buffer is sent (in binary, which is
+non-portable between different platforms).
+.TP
+.BI s sub-command
+This is a replacement for the previous
+.B S
+command, portable across different platforms. If the open device is a magnetic
+tape, return members of the magnetic tape status structure, as obtained with a
+.B MTIOCGET
+ioctl call. If the open device is not a magnetic tape, an error is returned. If
+the
+.B MTIOCGET
+operation was successful, the numerical value of the structure member is
+returned in decimal. The following sub commands are supported:
+.RS
+.TP
+.B T
+return the content of the structure member
+.B mt_type
+which contains the type of the magnetic tape device.
+.TP
+.B D
+return the content of the structure member
+.B mt_dsreg
+which contains the "drive status register".
+.TP
+.B E
+return the content of the structure member
+.B mt_erreg
+which contains the "error register". This structure member must be retrieved
+first because it is cleared after each
+.B MTIOCGET
+ioctl call.
+.TP
+.B R
+return the content of the structure member
+.B mt_resid
+which contains the residual count of the last I/O.
+.TP
+.B F
+return the content of the structure member
+.B mt_fileno
+which contains the file number of the current tape position.
+.TP
+.B B
+return the content of the structure member
+.B mt_blkno
+which contains the block number of the current tape position.
+.TP
+.B f
+return the content of the structure member
+.B mt_flags
+which contains MTF_ flags from the driver.
+.TP
+.B b
+return the content of the structure member
+.B mt_bf
+which contains the optimum blocking factor.
+.RE
+.PP