This BITS value reports a detailed qualifier bitmap for the coherent optical channel (och-os) on the line side of a pluggable transceiver - flags such as failed, mismatch, lowerLayerDown, notPresent, shutdown, degraded, idle, busy, and others - shown space-separated to explain the reason behind the administrative and operational status. An administrator reads these bits to go beyond a simple up/down status and understand exactly why a facility is impaired, for instance distinguishing a card that is physically absent from one that is present but administratively shut down. For example, on och-os the bitmap might show 'lowerLayerDown' rather than 'failed' when the outage is only because an upstream trunk carrying this facility has failed, telling the technician to investigate upstream instead of this port's own hardware.