16 files changed, 60 insertions, 72 deletions
diff --git a/guides/source/5_0_release_notes.md b/guides/source/5_0_release_notes.md
index dc631e5cb9..7c11fad7bf 100644
--- a/guides/source/5_0_release_notes.md
+++ b/guides/source/5_0_release_notes.md
@@ -300,9 +300,6 @@ Please refer to the [Changelog][action-view] for detailed changes.
     button on submit to prevent double submits.
     ([Pull Request](https://github.com/rails/rails/pull/21135))
 
-*   Downcase model name in form submit tags rather than humanize.
-    ([Pull Request](https://github.com/rails/rails/pull/22764))
-
 
 Action Mailer
 -------------
diff --git a/guides/source/action_view_overview.md b/guides/source/action_view_overview.md
index ce6f943e49..46116b1e47 100644
--- a/guides/source/action_view_overview.md
+++ b/guides/source/action_view_overview.md
@@ -173,7 +173,7 @@ would produce:
 ```json
 {
   "name": "Alex",
-  "email: "alex@example.com"
+  "email": "alex@example.com"
 }
 ```
 
diff --git a/guides/source/active_record_basics.md b/guides/source/active_record_basics.md
index fba89f9d13..d9e9466a33 100644
--- a/guides/source/active_record_basics.md
+++ b/guides/source/active_record_basics.md
@@ -361,7 +361,7 @@ class CreatePublications < ActiveRecord::Migration[5.0]
       t.string :publisher_type
       t.boolean :single_issue
 
-      t.timestamps null: false
+      t.timestamps
     end
     add_index :publications, :publication_type_id
   end
diff --git a/guides/source/active_record_migrations.md b/guides/source/active_record_migrations.md
index feb0de8eea..cd6b7fdd67 100644
--- a/guides/source/active_record_migrations.md
+++ b/guides/source/active_record_migrations.md
@@ -41,7 +41,7 @@ class CreateProducts < ActiveRecord::Migration[5.0]
       t.string :name
       t.text :description
 
-      t.timestamps null: false
+      t.timestamps
     end
   end
 end
@@ -847,7 +847,7 @@ class CreateProducts < ActiveRecord::Migration[5.0]
       create_table :products do |t|
         t.string :name
         t.text :description
-        t.timestamps null: false
+        t.timestamps
       end
     end
 
diff --git a/guides/source/asset_pipeline.md b/guides/source/asset_pipeline.md
index b6c612794c..17e21b1bc6 100644
--- a/guides/source/asset_pipeline.md
+++ b/guides/source/asset_pipeline.md
@@ -670,7 +670,7 @@ anymore, delete these options from the `javascript_include_tag` and
 `stylesheet_link_tag`.
 
 The fingerprinting behavior is controlled by the `config.assets.digest`
-initialization option (which defaults to `true` for production and development).
+initialization option (which defaults to `true`).
 
 NOTE: Under normal circumstances the default `config.assets.digest` option
 should not be changed. If there are no digests in the filenames, and far-future
diff --git a/guides/source/association_basics.md b/guides/source/association_basics.md
index 09ab64837a..0ffdf037f7 100644
--- a/guides/source/association_basics.md
+++ b/guides/source/association_basics.md
@@ -105,13 +105,13 @@ class CreateBooks < ActiveRecord::Migration[5.0]
   def change
     create_table :authors do |t|
       t.string :name
-      t.timestamps null: false
+      t.timestamps
     end
 
     create_table :books do |t|
       t.belongs_to :author, index: true
       t.datetime :published_at
-      t.timestamps null: false
+      t.timestamps
     end
   end
 end
@@ -136,13 +136,13 @@ class CreateSuppliers < ActiveRecord::Migration[5.0]
   def change
     create_table :suppliers do |t|
       t.string :name
-      t.timestamps null: false
+      t.timestamps
     end
 
     create_table :accounts do |t|
       t.belongs_to :supplier, index: true
       t.string :account_number
-      t.timestamps null: false
+      t.timestamps
     end
   end
 end
@@ -180,13 +180,13 @@ class CreateAuthors < ActiveRecord::Migration[5.0]
   def change
     create_table :authors do |t|
       t.string :name
-      t.timestamps null: false
+      t.timestamps
     end
 
     create_table :books do |t|
       t.belongs_to :author, index: true
       t.datetime :published_at
-      t.timestamps null: false
+      t.timestamps
     end
   end
 end
@@ -222,19 +222,19 @@ class CreateAppointments < ActiveRecord::Migration[5.0]
   def change
     create_table :physicians do |t|
       t.string :name
-      t.timestamps null: false
+      t.timestamps
     end
 
     create_table :patients do |t|
       t.string :name
-      t.timestamps null: false
+      t.timestamps
     end
 
     create_table :appointments do |t|
       t.belongs_to :physician, index: true
       t.belongs_to :patient, index: true
       t.datetime :appointment_date
-      t.timestamps null: false
+      t.timestamps
     end
   end
 end
@@ -308,19 +308,19 @@ class CreateAccountHistories < ActiveRecord::Migration[5.0]
   def change
     create_table :suppliers do |t|
       t.string :name
-      t.timestamps null: false
+      t.timestamps
     end
 
     create_table :accounts do |t|
       t.belongs_to :supplier, index: true
       t.string :account_number
-      t.timestamps null: false
+      t.timestamps
     end
 
     create_table :account_histories do |t|
       t.belongs_to :account, index: true
       t.integer :credit_rating
-      t.timestamps null: false
+      t.timestamps
     end
   end
 end
@@ -349,12 +349,12 @@ class CreateAssembliesAndParts < ActiveRecord::Migration[5.0]
   def change
     create_table :assemblies do |t|
       t.string :name
-      t.timestamps null: false
+      t.timestamps
     end
 
     create_table :parts do |t|
       t.string :part_number
-      t.timestamps null: false
+      t.timestamps
     end
 
     create_table :assemblies_parts, id: false do |t|
@@ -388,13 +388,13 @@ class CreateSuppliers < ActiveRecord::Migration[5.0]
   def change
     create_table :suppliers do |t|
       t.string  :name
-      t.timestamps null: false
+      t.timestamps
     end
 
     create_table :accounts do |t|
       t.integer :supplier_id
       t.string  :account_number
-      t.timestamps null: false
+      t.timestamps
     end
 
     add_index :accounts, :supplier_id
@@ -472,7 +472,7 @@ class CreatePictures < ActiveRecord::Migration[5.0]
       t.string  :name
       t.integer :imageable_id
       t.string  :imageable_type
-      t.timestamps null: false
+      t.timestamps
     end
 
     add_index :pictures, [:imageable_type, :imageable_id]
@@ -488,7 +488,7 @@ class CreatePictures < ActiveRecord::Migration[5.0]
     create_table :pictures do |t|
       t.string :name
       t.references :imageable, polymorphic: true, index: true
-      t.timestamps null: false
+      t.timestamps
     end
   end
 end
@@ -518,7 +518,7 @@ class CreateEmployees < ActiveRecord::Migration[5.0]
   def change
     create_table :employees do |t|
       t.references :manager, index: true
-      t.timestamps null: false
+      t.timestamps
     end
   end
 end
@@ -734,7 +734,7 @@ end
 With these changes, Active Record will only load one copy of the author object, preventing inconsistencies and making your application more efficient:
 
 ```ruby
-a = author.first
+a = Author.first
 b = a.books.first
 a.first_name == b.author.first_name # => true
 a.first_name = 'Manny'
diff --git a/guides/source/caching_with_rails.md b/guides/source/caching_with_rails.md
index f26019c72e..ebd67a4adb 100644
--- a/guides/source/caching_with_rails.md
+++ b/guides/source/caching_with_rails.md
@@ -119,25 +119,16 @@ If you want to cache a fragment under certain conditions, you can use
 
 The `render` helper can also cache individual templates rendered for a collection.
 It can even one up the previous example with `each` by reading all cache
-templates at once instead of one by one. This is done automatically if the template
-rendered by the collection includes a `cache` call. Take a collection that renders
-a `products/_product.html.erb` partial for each element:
-
-```ruby
-render products
-```
-
-If `products/_product.html.erb` starts with a `cache` call like so:
+templates at once instead of one by one. This is done by passing `cached: true` when rendering the collection:
 
 ```html+erb
-<% cache product do %>
-  <%= product.name %>
-<% end %>
+<%= render partial: 'products/product', collection: @products, cached: true %>
 ```
 
-All the cached templates from previous renders will be fetched at once with much
-greater speed. There's more info on how to make your templates [eligible for
-collection caching](http://api.rubyonrails.org/classes/ActionView/Template/Handlers/ERB.html#method-i-resource_cache_call_pattern).
+All cached templates from previous renders will be fetched at once with much
+greater speed. Additionally, the templates that haven't yet been cached will be
+written to cache and multi fetched on the next render.
+
 
 ### Russian Doll Caching
 
diff --git a/guides/source/command_line.md b/guides/source/command_line.md
index e865a02cbd..62d742fc28 100644
--- a/guides/source/command_line.md
+++ b/guides/source/command_line.md
@@ -65,11 +65,12 @@ $ bin/rails server
 => Booting Puma
 => Rails 5.0.0 application starting in development on http://0.0.0.0:3000
 => Run `rails server -h` for more startup options
-=> Ctrl-C to shutdown server
-Puma 2.15.3 starting...
-* Min threads: 0, max threads: 16
+Puma starting in single mode...
+* Version 3.0.2 (ruby 2.3.0-p0), codename: Plethora of Penguin Pinatas
+* Min threads: 5, max threads: 5
 * Environment: development
 * Listening on tcp://localhost:3000
+Use Ctrl-C to stop
 ```
 
 With just three commands we whipped up a Rails server listening on port 3000. Go to your browser and open [http://localhost:3000](http://localhost:3000), you will see a basic Rails app running.
diff --git a/guides/source/configuring.md b/guides/source/configuring.md
index 1d3ff6e6e7..d3a87c3820 100644
--- a/guides/source/configuring.md
+++ b/guides/source/configuring.md
@@ -157,7 +157,7 @@ pipeline is enabled. It is set to true by default.
 
 * `config.assets.manifest` defines the full path to be used for the asset precompiler's manifest file. Defaults to a file named `manifest-<random>.json` in the `config.assets.prefix` directory within the public folder.
 
-* `config.assets.digest` enables the use of MD5 fingerprints in asset names. Set to `true` by default in `production.rb` and `development.rb`.
+* `config.assets.digest` enables the use of MD5 fingerprints in asset names. Set to `true` by default.
 
 * `config.assets.debug` disables the concatenation and compression of assets. Set to `true` by default in `development.rb`.
 
@@ -191,6 +191,7 @@ The full set of methods that can be used in this block are as follows:
 * `scaffold_controller` different from `resource_controller`, defines which generator to use for generating a _scaffolded_ controller when using `rails generate scaffold`. Defaults to `:scaffold_controller`.
 * `stylesheets` turns on the hook for stylesheets in generators. Used in Rails for when the `scaffold` generator is run, but this hook can be used in other generates as well. Defaults to `true`.
 * `stylesheet_engine` configures the stylesheet engine (for eg. sass) to be used when generating assets. Defaults to `:css`.
+* `scaffold_stylesheet` creates `scaffold.css` when generating a scaffolded resource. Defaults to `true`.
 * `test_framework` defines which test framework to use. Defaults to `false` and will use Minitest by default.
 * `template_engine` defines which template engine to use, such as ERB or Haml. Defaults to `:erb`.
 
diff --git a/guides/source/contributing_to_ruby_on_rails.md b/guides/source/contributing_to_ruby_on_rails.md
index 0f98d12217..12d0280116 100644
--- a/guides/source/contributing_to_ruby_on_rails.md
+++ b/guides/source/contributing_to_ruby_on_rails.md
@@ -367,7 +367,7 @@ Finally,
 $ bundle exec rake test
 ```
 
-will now run the four of them in turn.
+will now run the three of them in turn.
 
 You can also run any single test separately:
 
diff --git a/guides/source/debugging_rails_applications.md b/guides/source/debugging_rails_applications.md
index faf475c294..877c87e9fa 100644
--- a/guides/source/debugging_rails_applications.md
+++ b/guides/source/debugging_rails_applications.md
@@ -314,11 +314,12 @@ For example:
 => Booting Puma
 => Rails 5.0.0 application starting in development on http://0.0.0.0:3000
 => Run `rails server -h` for more startup options
-=> Ctrl-C to shutdown server
-Puma 2.15.3 starting...
-* Min threads: 0, max threads: 16
+Puma starting in single mode...
+* Version 3.0.2 (ruby 2.3.0-p0), codename: Plethora of Penguin Pinatas
+* Min threads: 5, max threads: 5
 * Environment: development
 * Listening on tcp://localhost:3000
+Use Ctrl-C to stop
 
 
 Started GET "/" for 127.0.0.1 at 2014-04-11 13:11:48 +0200
diff --git a/guides/source/documents.yaml b/guides/source/documents.yaml
index 2cf613f47f..03943d0f25 100644
--- a/guides/source/documents.yaml
+++ b/guides/source/documents.yaml
@@ -116,7 +116,7 @@
       name: The Rails Initialization Process
       work_in_progress: true
       url: initialization.html
-      description: This guide explains the internals of the Rails initialization process as of Rails 4.
+      description: This guide explains the internals of the Rails initialization process.
     -
       name: Autoloading and Reloading Constants
       url: autoloading_and_reloading_constants.html
diff --git a/guides/source/engines.md b/guides/source/engines.md
index c5fc2f73b4..eafac4828c 100644
--- a/guides/source/engines.md
+++ b/guides/source/engines.md
@@ -799,7 +799,7 @@ before the article is saved. It will also need to have an `attr_accessor` set up
 for this field, so that the setter and getter methods are defined for it.
 
 To do all this, you'll need to add the `attr_accessor` for `author_name`, the
-association for the author and the `before_save` call into
+association for the author and the `before_validation` call into
 `app/models/blorgh/article.rb`. The `author` association will be hard-coded to the
 `User` class for the time being.
 
@@ -807,7 +807,7 @@ association for the author and the `before_save` call into
 attr_accessor :author_name
 belongs_to :author, class_name: "User"
 
-before_save :set_author
+before_validation :set_author
 
 private
   def set_author
@@ -1209,7 +1209,7 @@ module Blorgh::Concerns::Models::Article
     attr_accessor :author_name
     belongs_to :author, class_name: "User"
 
-    before_save :set_author
+    before_validation :set_author
 
     private
       def set_author
diff --git a/guides/source/getting_started.md b/guides/source/getting_started.md
index 4431512eda..a615751eb5 100644
--- a/guides/source/getting_started.md
+++ b/guides/source/getting_started.md
@@ -690,7 +690,7 @@ class CreateArticles < ActiveRecord::Migration[5.0]
       t.string :title
       t.text :text
 
-      t.timestamps null: false
+      t.timestamps
     end
   end
 end
@@ -1558,9 +1558,9 @@ class CreateComments < ActiveRecord::Migration[5.0]
     create_table :comments do |t|
       t.string :commenter
       t.text :body
-      t.references :article, index: true, foreign_key: true
+      t.references :article, foreign_key: true
 
-      t.timestamps null: false
+      t.timestamps
     end
   end
 end
diff --git a/guides/source/initialization.md b/guides/source/initialization.md
index 156f9c92b4..89e5346d86 100644
--- a/guides/source/initialization.md
+++ b/guides/source/initialization.md
@@ -3,8 +3,8 @@
 The Rails Initialization Process
 ================================
 
-This guide explains the internals of the initialization process in Rails
-as of Rails 4. It is an extremely in-depth guide and recommended for advanced Rails developers.
+This guide explains the internals of the initialization process in Rails.
+It is an extremely in-depth guide and recommended for advanced Rails developers.
 
 After reading this guide, you will know:
 
@@ -356,8 +356,6 @@ private
   def print_boot_information
     ...
     puts "=> Run `rails server -h` for more startup options"
-    ...
-    puts "=> Ctrl-C to shutdown server" unless options[:daemonize]
   end
 
   def create_tmp_directories
diff --git a/guides/source/layouts_and_rendering.md b/guides/source/layouts_and_rendering.md
index 614ca4dbe1..2722789c49 100644
--- a/guides/source/layouts_and_rendering.md
+++ b/guides/source/layouts_and_rendering.md
@@ -149,23 +149,22 @@ render template: "products/show"
 
 #### Rendering an Arbitrary File
 
-The `render` method can also use a view that's entirely outside of your application (perhaps you're sharing views between two Rails applications):
-
-```ruby
-render "/u/apps/warehouse_app/current/app/views/products/show"
-```
-
-Rails determines that this is a file render because of the leading slash character. To be explicit, you can use the `:file` option (which was required on Rails 2.2 and earlier):
+The `render` method can also use a view that's entirely outside of your application:
 
 ```ruby
 render file: "/u/apps/warehouse_app/current/app/views/products/show"
 ```
 
-The `:file` option takes an absolute file-system path. Of course, you need to have rights to the view that you're using to render the content.
+The `:file` option takes an absolute file-system path. Of course, you need to have rights
+to the view that you're using to render the content.
+
+NOTE: Using the `:file` option in combination with users input can lead to security problems
+since an attacker could use this action to access security sensitive files in your file system.
 
 NOTE: By default, the file is rendered using the current layout.
 
-TIP: If you're running Rails on Microsoft Windows, you should use the `:file` option to render a file, because Windows filenames do not have the same format as Unix filenames.
+TIP: If you're running Rails on Microsoft Windows, you should use the `:file` option to
+render a file, because Windows filenames do not have the same format as Unix filenames.
 
 #### Wrapping it up
 
@@ -238,7 +237,7 @@ TIP: This is useful when you're rendering a small snippet of HTML code.
 However, you might want to consider moving it to a template file if the markup
 is complex.
 
-NOTE: When using `html:` option, HTML entities will be escaped if the string is not marked as HTML safe by using `html_safe` method.  
+NOTE: When using `html:` option, HTML entities will be escaped if the string is not marked as HTML safe by using `html_safe` method.
 
 #### Rendering JSON