The Vendor_ID Supporting Reference field is not populated for Period End Accrual entries

We have set supporting references to capture the PO_NUMBER, SUPPLIER_NAME, and SUPPIER_NUMBER for Period End Accruals.  When we view the supporting references for these journals, only the PO_NUMBER and SUPPLIER_NAME appear.  We are using the source name " Vendor Identifier", for event class, "Period End Accrual", with the application, "Cost Management".  The application and event class for the other 2 supporting references are the same.  Is there a way to have the Vendor Identifier included in these supporting references?