Service Guide
Page 119
... a basic physical extension or sub-enclosure of location identifier -- Primarily, the [.n] sub-location notation is a sub-location instance number (where applicable). for example, a drawer in a rack (U1.2) or a riser card on integrated SCSI bus 1 from Planar 2), rather than P1-C1-C1 P2-Z1-A3.1 (LUN 1 at SCSI ID 3 on an I/O board...
... a basic physical extension or sub-enclosure of location identifier -- Primarily, the [.n] sub-location notation is a sub-location instance number (where applicable). for example, a drawer in a rack (U1.2) or a riser card on integrated SCSI bus 1 from Planar 2), rather than P1-C1-C1 P2-Z1-A3.1 (LUN 1 at SCSI ID 3 on an I/O board...