This read-only SecondaryState supplies qualifying detail about the condition of the BITS 16 Port Expansion Card beyond the simple enabled/disabled operational state, such as reasons a card might be degraded. It matters operationally because two cards can share the same operational state yet have different secondary states, so this value helps an administrator distinguish a fully healthy BITS 16 Port Expansion Card from one that is running with a caveat. For example, a technician troubleshooting the BITS 16 Port Expansion Card checks this object alongside the operational state to see whether the card is merely unequipped versus actively failed.