Originally Posted by
julietnov
What about the ZN inventory bucket?
ZN used to be used as inventory control for standard awards before they allowed all passengers last-seat access (at inflated prices). Today, I think we've sussed out that it can be used for the Skip the Waitlist feature with PlusPoints, but (a) you'd need to be a 1K traveler to use this, and (b) Skip the Waitlist is only available on long-haul South America routes.
TL/DR: You can safely ignore ZN.