diff --git a/Tutorial_Docs/Associations.MD b/Tutorial_Docs/Associations.MD
index 7ebbd8a..caa453e 100644
--- a/Tutorial_Docs/Associations.MD
+++ b/Tutorial_Docs/Associations.MD
@@ -45,6 +45,13 @@ You would then access the methods added to the model in rails console via
 pages.editors
 ```
 
+### foreign_key
+If your foreign key is something other than the associated class_name, you must specify a different foreign key
+```
+belongs_to :editor, :class_name => "AdminUser", :foreign_key => "admin_user_id" # because foreign key is not called editor_id
+
+```
+
 ## Defining editors on pages
 In rails console, create a new user
 ```
@@ -60,3 +67,18 @@ Associate the new user to the page
 ```
 page.editors << me
 ```
+
+
+## Rich Many-to-many
+Create new model for rich join table
+```
+rails generate model SectionEdit
+```
+
+Adding join between tables
+```
+edit = SectionEdit.new
+```
+```
+edit.summary = "Edited some content"
+```
diff --git a/app/models/admin_user.rb b/app/models/admin_user.rb
index f5ecb98..890a856 100644
--- a/app/models/admin_user.rb
+++ b/app/models/admin_user.rb
@@ -1,6 +1,7 @@
 class AdminUser < ApplicationRecord
 
   has_and_belongs_to_many :pages
+  has_many :section_edits
 
     # To configure a different table name.
     # self.table_name = "admin_users"
diff --git a/app/models/section.rb b/app/models/section.rb
index ec21dc1..b88d176 100644
--- a/app/models/section.rb
+++ b/app/models/section.rb
@@ -1,2 +1,4 @@
 class Section < ApplicationRecord
+  has_many :section_edits
+
 end
diff --git a/app/models/section_edit.rb b/app/models/section_edit.rb
new file mode 100644
index 0000000..5d3dcdd
--- /dev/null
+++ b/app/models/section_edit.rb
@@ -0,0 +1,5 @@
+class SectionEdit < ApplicationRecord
+
+  belongs_to :editor, :class_name => "AdminUser", :foreign_key => "admin_user_id" # because foreign key is not called editor_id
+  belongs_to :section
+end
diff --git a/db/migrate/20160927050319_create_section_edits.rb b/db/migrate/20160927050319_create_section_edits.rb
new file mode 100644
index 0000000..8f46de3
--- /dev/null
+++ b/db/migrate/20160927050319_create_section_edits.rb
@@ -0,0 +1,12 @@
+class CreateSectionEdits < ActiveRecord::Migration[5.0]
+
+  def change
+    create_table :section_edits do |t| # rich many-to-many does require primary key
+      t.references :admin_user
+      t.references :section
+      t.string :summary
+      t.timestamps
+    end
+  end
+
+end
diff --git a/test/fixtures/section_edits.yml b/test/fixtures/section_edits.yml
new file mode 100644
index 0000000..80aed36
--- /dev/null
+++ b/test/fixtures/section_edits.yml
@@ -0,0 +1,11 @@
+# Read about fixtures at http://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html
+
+# This model initially had no columns defined. If you add columns to the
+# model remove the '{}' from the fixture names and add the columns immediately
+# below each fixture, per the syntax in the comments below
+#
+one: {}
+# column: value
+#
+two: {}
+# column: value
diff --git a/test/models/section_edit_test.rb b/test/models/section_edit_test.rb
new file mode 100644
index 0000000..b1c59d8
--- /dev/null
+++ b/test/models/section_edit_test.rb
@@ -0,0 +1,7 @@
+require 'test_helper'
+
+class SectionEditTest < ActiveSupport::TestCase
+  # test "the truth" do
+  #   assert true
+  # end
+end