Completed Sales Orders not Moving to History

Just finished a little Sales Order cleanup for a customer who had 2 sales orders in the system that  were fully invoiced, yet the SO's didn't automatically move to History.  Turns out that if a quantity on a Sales Order is reduced to zero, or cancelled, prior to invoicing, the SO will not move to History automatically.  You have to manually move them using Sales>>Utilities>>Reconcile-Remove Sales Documents.

 

 

 

Interesting.