Is there a standard way to flag a purchase order for manual invoice verification so that we can verify that the appropriate documentation has been provided (attached) with the invoice? For example, we have a service provided in the field and the goods receipt is performed to timely book the cost. However, we don't want to allow the automatic payment of the invoice until we validate that included with the invoice was documentation that isn't available until after the work is performed and comes from the supplier's back-office. We want the invoice workflow to notify a person to verify the appropriate documentation was attached and then that person can release the invoice to be queued for payment.