docs: public static String createURLTitle(final String title) {
          String baseTitle = title;
          // Remove XML Elements from the Title.
          baseTitle = baseTitle.replaceAll("</(.*?)>", "").replaceAll("<(.*?)>", "");
  
          // Check if the title starts with an invalid sequence
          final Matcher invalidSequenceMatcher = STARTS_WITH_INVALID_SEQUENCE_RE.matcher(baseTitle);
          if (invalidSequenceMatcher.find()) {
              baseTitle = invalidSequenceMatcher.group("EverythingElse");
          }
  
          // Start by removing any prefixed numbers (you can't start an xref id with numbers)
          final Matcher matcher = STARTS_WITH_NUMBER_RE.matcher(baseTitle);
          if (matcher.find()) {
              final String numbers = matcher.group("Numbers");
              final String everythingElse = matcher.group("EverythingElse");
  
              if (numbers != null && everythingElse != null) {
                  final NumberFormat formatter = new RuleBasedNumberFormat(RuleBasedNumberFormat.SPELLOUT);
                  final String numbersSpeltOut = formatter.format(Integer.parseInt(numbers));
                  baseTitle = numbersSpeltOut + everythingElse;
  
                  // Capitalize the first character
                  if (baseTitle.length() > 0) {
                      baseTitle = baseTitle.substring(0, 1).toUpperCase() + baseTitle.substring(1, baseTitle.length());
                  }
              }
          }
  
          // Escape the title
          final String escapedTitle = DocBookUtilities.escapeTitle(baseTitle);
  
          // We don't want only numeric fixed urls, as that is completely meaningless.
          if (escapedTitle.matches("^\\d+$")) {
              return "";
          } else {
              return escapedTitle;
          }
      }