VbzCart/ui/terms/restock/request/exp

This is the quantity we are expecting to receive from the supplier. If it is blank, we're expecting to receive the amount that was ordered.

What most often happens is that the supplier does not have as many in stock as we want; if they helpfully inform us about this before the restock arrives, then we use this field to record the amount we've been told to expect.

Occasionally, a supplier may throw in extra units not ordered (either free or to fill a required minimum); this field can be used to record that fact as well, if we find out about it before receiving the shipment.

Either way, if we only find out about a quantity change when the restock shipment arrives, then this information gets recorded in the restock receipt data instead of here in the restock request data.