This object reports the PmBinState of this collection bin, as stated in the MIB description. This flags whether the data in this Curr bin for this specific egress queue on the port is a complete, trustworthy sample or a partial/suspect one -- for instance if the device's clock was adjusted, the card reset, or NE time sync was lost partway through the window -- which matters because a partial bin's counters can look artificially low purely due to the shortened collection time, not because traffic actually improved. For example, an admin building a 24-hour drop-rate trend graph would exclude or flag any bin reporting a non-valid state rather than plotting its (misleadingly low) counter values next to full, valid bins.