I am looking to modify a standard PDF for an Invoice and would like to include a reference to the item fulfillment record. I've used {itemfulfillment} without any luck. I know this is outside AdvancePDF, but wondering if there's something quick to resolve this. Thanks

I believe you'd have to store the reference to the item fulfillment(s) in a custom field on the invoice to be able to reference it in the PDF template.