Forum OpenACS Q&A: Response to Character encoding of ns_xml

You probably can't unless you're willing to modify ns_xml. If you are then since ns_xml is just a thin wrapper around libxml (http://xmlsoft.org/) step one would be to figure out how to do it in pure libxml and step two would be to add relevant capability to ns_xml (which would probably be trivial once you figure out how to control libxml to do what you want).