Fujitsu MAA3182SC Oem Manual page 140

(2) Reserve Right and Third Party Reserve Function
If the "3rd Pty" bit in byte 1 of the CDB is "0," the IDD is reserved by the INIT which issued
this command and that INIT has the Reserve right for the IDD.
If the "3rd Pty" bit is "1," the third party reserve function is specified. An INIT which
specifies the third party reserve function and issues this command can reserve the IDD for use
by another SCSI device. In this case, this command reserves the IDD for the SCSI device
(called the third party device) with the SCSI ID specified in the "3rd Pty Dev ID" field in byte
1 of the CDB. Even it the IDD is reserved for another SCSI device using the third party
reserve function the reserve right for that ID resides with the INIT that issued this command.
Therefore, in order to release that reserve state, it is necessary for the INIT that issued this
command to issue a RELEASE command (shown in item 3.1.13) with the third party release
function specified. Also, the conditions for maintaining the reserve state established by the
third party reserve function are the same as in the case where the third party reserve function is
not used. (See item (1).)
Please not that since only 3 bits are defined for the "3rd Pty Dev ID" field, this command is
valid for the third party reserve function with respect to only SCSI devices with SCSI ID 7 to
0.
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