Nonnettable inventory is one type of unavailable inventory, but there may also be some nettable inventory that is unavailable to be picked.

Theſe, who have nature's ſteps with care purſued, That matter is with active force endued, That all its parts magnetic power exert, And to each other gravitate, aſſert.

He is the key player on his soccer team.

Unfalsifiability: The main problem with any particular conspiracy theory is not that it's wrong, but that it's inarguable; not that it's false, but that it is unfalsifiable.