I would like to print item labels with a custom field. We were told that it is not possible to add a custom field to the advanced pdf template for item labels. But it is possible in the basic pdf layout. However, when the item record has a value in the UPC Code field, the barcode disappears. Apparently, we need to keep the UPC and want to avoid creating a custom field to replace UPC. Is this really the standard behavior?

Unfortunately, the item label is a weird one. It is very limited on what data you can get to with an advanced PDF template. But, you should be able to print a barcode of the UPC though. It's not just label.upc though, it's label.skuUpcBarcode