All narrow character interfaces, such as RWCString, char, and char* inserters and extractors, take or produce only UTF-8 encoded characters. If you are using an XML output stream with a narrow character interface, and you try to insert into the stream a non-UTF-8 character, the stream may produce an incorrect document. If your character encoding is UTF-16, you may use RWBasicUString from the Essential Tools Module to convert it to UTF-8. If your encoding is other than UTF-8 or UTF-16, you will need to use RWUString and the conversion utility classes from the Internationalization Module. See Using the XML Streams Package with the Internationalization Module.