docs: protected void addOutlineEntry(StringBuilder outline, int level, String sectionNumber, String title,
  			String sectionId, boolean htmlOutput) {
  		if (htmlOutput) {
  			indent(outline, level - 1, "  "); //$NON-NLS-1$
  			outline.append("<li><a href=\"#"); //$NON-NLS-1$
  			outline.append(sectionId);
  			outline.append("\">"); //$NON-NLS-1$
  			if (isAutoSectionNumbering() && !Strings.isEmpty(sectionNumber)) {
  				outline.append(sectionNumber).append(". "); //$NON-NLS-1$
  			}
  			outline.append(title);
  			outline.append("</a></li>"); //$NON-NLS-1$
  		} else {
  			final String prefix = "*"; //$NON-NLS-1$
  			final String entry;
  			outline.append("> "); //$NON-NLS-1$
  			indent(outline, level - 1, "\t"); //$NON-NLS-1$
  			if (isAutoSectionNumbering()) {
  				entry = MessageFormat.format(getOutlineEntryFormat(), prefix,
  						Strings.emptyIfNull(sectionNumber), title, sectionId);
  			} else {
  				entry = MessageFormat.format(getOutlineEntryFormat(), prefix, title, sectionId);
  			}
  			outline.append(entry);
  		}
  		outline.append("\n"); //$NON-NLS-1$
  	}