code: def write_parent (self, url_data):
          
          self.write(u"<tr><td>"+self.part("parenturl")+
                     u'</td><td><a target="top" href="'+
                     url_data.parent_url+u'">'+
                     cgi.escape(url_data.parent_url)+u"</a>")
          if url_data.line > 0:
              self.write(_(", line %d") % url_data.line)
          if url_data.column > 0:
              self.write(_(", col %d") % url_data.column)
          if url_data.page > 0:
              self.write(_(", page %d") % url_data.page)
          if not url_data.valid:
              # on errors show HTML and CSS validation for parent url
              vhtml = validate_html % {'uri': url_data.parent_url}
              vcss = validate_css % {'uri': url_data.parent_url}
              self.writeln()
              self.writeln(u'(<a href="'+vhtml+u'">HTML</a>)')
              self.write(u'(<a href="'+vcss+u'">CSS</a>)')
          self.writeln(u"</td></tr>")
docs: Write url_data.parent_url.