The template overrides and the AppendixObject source.

default-appendix-html-appendix_entry.erb

<h3><%= object.title %></h3>
<%= yieldall :index => 0 %>

default-appendix-html-setup.rb

def init
  sections :appendix_entry, [T('docstring')]
end

def appendix_entry
  erb :entry
end

default-class-html-appendix.erb

<div class="appendix">
  <h2>Appendix</h2>
  # perhaps i should select the :appendix children of object instead of using the Registry?
  <% YARD::Registry.all(:appendix).select { |o| o.namespace == owner }.each do |o| %>
    <div class="appendix_entry">
      <%= o.format(:format => :html) %>
    </div>
  <% end %>
</div>

default-class-html-setup.rb

include T('default/module/html')

def init
  super
  sections.push(:appendix, [ T('docstring') ])
end

def appendix(*args)
  erb(:appendix)
end

lib-yard-appendix-code_objects-appendix_object.rb

require 'yard/code_objects/base'
require 'yard/code_objects/class_object'
require 'yard/code_objects/method_object'

module YARD
  module CodeObjects
    class AppendixObject < Base
      attr_reader :title, :body, :name
      
      # def type; "appendix" end
      
      def initialize(ns, docstring)
        @name = "Appendix_#{index_in_namespace(ns)}"
        
        super(ns, @name.to_sym)
        
        @type  = :appendix
        
        # extract title from the first line
        @title = 
          docstring.lines.any? &&
          docstring.lines.first.gsub(/\s*@appendix/, '').strip
        
        @body =
           docstring.
           split("\n")[1..-1].
           # reject { |s| s.empty? }[1..-1].
           # collect { |s| s.strip }.
           join("\n")
           
        @docstring = DocstringParser.new.parse(@body).to_docstring
      end
   
      def inspect
        "#<yardoc #{type} #{path} #{title}>"
      end
      
      def to_s
        @title
      end
      
      private
      
      def sanitize_title
      end
      
      def index_in_namespace(ns)
        @@indexes ||= {}
        @@indexes[ns.to_s] ||= 0
        @@indexes[ns.to_s] += 1
      end
      
    end
  end
end