Similar to the "Customer Reference" field that is available for Sales Orders, it would be extremely useful to have a "Vendor Reference" field available for purchases.
This would make is much easier to categorize and search past purchases.
I cannot believe that such a simple field has not been added. I just started using the system. I have never actually seen an inventory system that doesn't have the ability to enter a reference number provided by a supplier. This is not the same as the invoice number.