Quantum ACL 4/52 Supplementary Manual page 104

ACL 4/52 Software Interface Guide
Document 6211225-03
Version 3.0
Invert
Source Storage Element Address
Primary Volume Tag Information
3-70
The invert field is not supported and is set to zero.
The Source Storage Element Address represents the address of the
last storage element which held the cartridge. The SValid field
indicates whether or not this information is valid.
If the Volume Tag information was requested in the command
block, the Primary Volume Tag Information field will be included
in the element descriptor. See Table 44 for format.
SCSI Interface