use of CheckConditionVendors parameters

Hello Experts,

I have seen the below Parameter in VND Section of AP Project Guide,

Parameter                          Type                     Description

CheckConditionVendors      YES/NO             If set to YES, an alternate vendor ID will be allowed for a PO-based invoice if it matches a vendor held within a condition record (e.g. for planned

                                                                      freight) behind a purchase order line

Please advise How I can utilize this condition. can we process one PO for multiple vendor in WFR using the above parameter if so please advise how I can achieve it in WFR.

Thanks

Sanjeev