Bucket for Unreceived POs

A frequent complaint I hear is that an invoice cannot be entered and linked to a PO if the PO has not been fully received. The expected workflow is for AP to put invoices such as this to the side, wait a few days, then go back in and try again. If they leave the invoice listed as an incomplete, it can easily get "lost" it's easier for them to delete the invoice, and completely start from scratch. It would be nice if unreceived invoices could be put in a bucket of some sort or worked into the Invoice-PO Discrepancies under a different status so that they are easily able to be reviewed. It would even be better if you could upload a PDF copy of the invoice into the invoice you are working on so that you do not need to keep so much paper and can work through these discrepancies faster.