code: public void addRdfDescription(XmpSchema s) throws IOException {
  		writer.write("<rdf:Description rdf:about=\"");
  		writer.write(about);
  		writer.write("\" ");
  		writer.write(s.getXmlns());
  		writer.write(">");
  		writer.write(s.toString());
  		writer.write("</rdf:Description>\n");
  	}
docs: Adds an rdf:Description.
  @param s
  @throws IOException