THIS DOCUMENT REPRESENTS THE REVISED TEXT FOR THE DESCRIPTION OF THE DENSITY 
CODE FIELD IN THE MODE SENSE / MODE SELECT BLOCK DESCRIPTOR FOR SEQUENTIAL 
ACCESS DEVICES ON PAGE 9-41 OF SCSI-2, REVISION 6a.

  For the MODE SELECT command, the density code field of the sequential-access 
device block descriptor indicates the density selected by the initiator for 
use in subsequent read and write operations.  For devices capable of automatic 
density recognition, the density code selected by the initiator may be 
overridden by the target for a subsequent read operation if the selected value 
does not match the current recorded density of the medium.

  For the MODE SENSE command, the density code field reflects the current 
operating density of the device.  For some devices, the default density code 
value returned in response to a MODE SENSE command may change dynamically to 
match the most recently selected density.

  The density code value returned in response to a MODE SENSE command shall be 
as described below:

  (1)  Following a UNIT ATTENTION condition for a power on or hard reset, 
while not ready, the target shall report the default or only density.

  (2)  Following a UNIT ATTENTION condition for a not ready to ready 
transition, the target shall:

    (a) report the default or only density if no attempt has been made by the 
  target to determine the density.
    (b) report the default or only density if the target cannot automatically 
  determine the density from the medium.
    (c) report the current recorded density if the target can automatically 
  determine the density from the medium.

  (3)  Following a successful read operation at or after beginning-of-medium, 
the target shall report a density code value reflecting the recorded density 
of the medium. For some implementations, the target may automatically 
determine this value from the medium.  For devices not capable of automatic 
density determination, the density code value is provided by the preceding 
MODE SELECT command.
   
  (4)  Following an unsuccessful read operation or a successful write 
operation, while at beginning-of-partition, the target shall:

    (a) report a density code value as described for item 2 if no preceding 
  MODE SELECT command has been issued for the currently mounted volume.
    (b) report a density code value as provided by the last successful MODE 
  SELECT command for the currently mounted volume.

  (5)  Following a successful unload operation, while not ready, the target 
shall report the most recent density code value as determined by items 2-4 
above.