Running under the understanding that you should not ever delete invoices (which I mistakenly did with one during our first week of operating our new Zencart store) how do you cancel a sale yet keep the invoice? Add a no-sale or cancelled option under "Localization>Orders Status"?

I amended mine so far to include:
Pending (order has been placed but not processed yet)
Deleted (thinking of eliminating this because it does DELETE the invoice entirely)
Order Update (for sending information or questions about the order to customer)
Back-Ordered (for an item that's back-ordered)

This gives me a good visual order status at a glance on the admin orders page.