I have a custom record type that has a child record defined. The child records are showing on the parent form under the tab i defined, but the child list passed to the advanced print template appears to be empty for the record. I also note that adding &xml=T to the URL for the parent record omits the children from the XML output. Any pointers as to where I need to be looking to get the data visible in the template?

Not that I've done it myself, but potentially investigate the PDF from search https://system.netsuite.com/app/help/helpcenter.nl?fid=section_4823423235.html&whence=