Enhancement request: Allow for negative payments in Point of Sale. In Point of Sale module, you are allowed to edit the cost of a sale item, and change the amount tendered. But the system won't allow you to input negative numbers for cost. For example, if we want to refund a patron $20 from their print account, we take $20 out of the register and hand it to the patron. Point of Sale has no way to record this refund, since the money was collected long ago and over many transactions (i.e. there is no specific transaction to refund). As a result, the register in POS will be over by $20. If we could make a sale of an item with a cost of -20.00, we could account for this refund and balance the POS register correctly.
Maybe instead of negative amounts, a specific refund functionality would be better?