Note to supplier in iProcurement requisition

Our users are looking for a field "Note to Supplier" in the iprocurement module while creating a non-catalog request. Can you guide us if it is a field that is available in the standard functionality that can be enabled or will it be a customization. The idea is that the requisitioner will enter the "Note to Supplier" and that would be added onto the "Note to Supplier" field on the PO during autocreate.