// field name in the XML element.
// - a field with tag ",chardata" is written as character data,
// not as an XML element.
+// - a field with tag ",cdata" is written as character data
+// wrapped in one or more <![CDATA[ ... ]]> tags, not as an XML element.
// - a field with tag ",innerxml" is written verbatim, not subject
// to the usual marshalling procedure.
// - a field with tag ",comment" is written as an XML comment, not