Hi @mohammadnawaz51, are you referring to the Printed Form Shipment Confirmation? You can easily say on it that there are Items on Backorder, and you can use the total SO Quantity on Backorder which is already in the SOOrder Table linked already on the document to include a message that there are x number of items on Backorder.
I have tried before to use the relations to go in through the back-door to the SO Line table to spell out on the Shipment Confirmation which Items are on BackOrder, but I have never had luck successfully doing that.
I would then do a subreport of the SOLines on the Shipment Confirmation. I am not sure you’ll be able to get them in the Details section with the rest of the lines from the Shipment, but you could put them up in the header or down in the footer of the Shipment Confirmation. You can set it so it only displays if SOOrder Qty on Backorder>0