Punchouts - Model 2b - Direct (cXML) Vendor Hosted Site -- BUYERCOOKIE???

Hi,

In our environment, we have close to ten punchouts for US and in the cXML there is no PunchOutSetupRequest tag with BuyerCookie.  A new vendor we are setting up Punchout for in Canada is saying we need this.  Is that true?  How and where would I set this up?

<PunchOutSetupRequest operation="create">

                                <BuyerCookie>value</BuyerCookie>

Thanks and regards,

Pete