# File lib/rdoc/markup/to_tt_only.rb, line 74
  def tt_sections text
    flow = @am.flow text.dup

    flow.each do |item|
      case item
      when String then
        @res << item if in_tt?
      when RDoc::Markup::AttrChanger then
        off_tags res, item
        on_tags res, item
      when RDoc::Markup::Special then
        @res << convert_special(item) if in_tt? # TODO can this happen?
      else
        raise "Unknown flow element: #{item.inspect}"
      end
    end

    res
  end