Hello,
The trigger line is Postscript code that is basically read and discarded afterwards by the printer. When designing a document in PlanetPress you should never have the trigger present. The trigger should only be added when sending jobs to a printer resident document.
In the case of line printer, having the trigger there does not make the data file invlaid, however, in XML, having those 2 lines will make your data file invlaid XML.
When sending the XML data to a printer with a resisent form, these 2 lines will not cause a problem since the printer discards them after reading.