documentation for automated seating

I have never used the automated seating feature before, but think that it might be able to resolve a situation for us.  The catch is that I can't find documentation for how it works anywhere! 

Does anyone have information on exactly what the automated seating does, and what information it needs?  Does it need to have an unseated line item on an order or can it add a performance to an order and seat it?

Any help on this would be greatly appreciated.

Thanks,

Boann