3620133 - When does system send IdReference tag in the ShipTo section of the Purchase Order to Business Network?

When does system send the below IdReference tag in the Ship To section of the Purchase Order to Business Network?

<ShipTo>

<IdReference
            domain="gstID"
            identifier="XXXXXXXXXXX"/>

</ShipTo>

ship to address, purchase order, sap ariba, missing address, GST number, sync template, line item, external field, cus_CustomerGSTIN, header level, tax line item, PO, ordered status, test realm, production realm , KBA , BNS-ARI-PUR-PO , Purchase Orders , BNS-ARI-PUR-REQ , Requisitioning , How To