code: protected void onUnknownDocType(AppendingStringBuffer response) {
  		IRequestablePage responsePage = getResponsePage();
  
  		String detectionString = getFirstCharacters(response, 128);
  
  		if (responsePage != null) {
  			log.info("No or unknown DOCTYPE detected for page {}: {}",
  					responsePage.getClass().getName(), detectionString);
  		} else {
  			log.info("No or unknown DOCTYPE detected: {}", detectionString);
  		}
  	}
docs: Called when no known {@link DocType} could be determined from the
  {@code responseBuffer}. The markup is not validated.
  
  @param responseBuffer
  the response markup that could not be validated.