code: private List<String> buildUrls(List<String> references) {
  		List<String> urls = new ArrayList<String>(references.size());
  		for (String url : references) {
  			if (url.toUpperCase().startsWith("RFC")) {
  				url = RFC_REFERENCE_BASE_URL + url;
  			} else if (url.startsWith("http")) {
  				// already an URL so do nothing
  			} else {
  				url = MIME_TYPE_REFERENCE_BASE_URL + "#" + url;
  			}
  			urls.add(url);
  		}
  		return urls;
  	}
docs: Creates the URL of each reference (such as RFC document)