HP 2600fx - Optical Disk Drive Command Reference Manual page 260

Access When set to 1, access to the element by the Medium
Transport Element is allowed.
Except When set to 1, the element is in an abnormal state.
Imp/Exp When set to 1, the operator inserted the cartridge into
the mailslot.
When set to 0, the jukebox mechanism puts the
cartridge in the mailslot.
Full When set to 1, the element contains a cartridge.
Chapter 3
Jukebox SCSI-2 Command Set
Read Element Status Command (B8H)
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