1 files changed, 15 insertions, 5 deletions
diff --git a/guides/source/rails_on_rack.md b/guides/source/rails_on_rack.md
index aa1476ecc0..8d66942e31 100644
--- a/guides/source/rails_on_rack.md
+++ b/guides/source/rails_on_rack.md
@@ -13,12 +13,12 @@ After reading this guide, you will know:
 
 --------------------------------------------------------------------------------
 
-WARNING: This guide assumes a working knowledge of Rack protocol and Rack concepts such as middlewares, url maps and `Rack::Builder`.
+WARNING: This guide assumes a working knowledge of Rack protocol and Rack concepts such as middlewares, url maps, and `Rack::Builder`.
 
 Introduction to Rack
 --------------------
 
-Rack provides a minimal, modular and adaptable interface for developing web applications in Ruby. By wrapping HTTP requests and responses in the simplest way possible, it unifies and distills the API for web servers, web frameworks, and software in between (the so-called middleware) into a single method call.
+Rack provides a minimal, modular, and adaptable interface for developing web applications in Ruby. By wrapping HTTP requests and responses in the simplest way possible, it unifies and distills the API for web servers, web frameworks, and software in between (the so-called middleware) into a single method call.
 
 Explaining how Rack works is not really in the scope of this guide. In case you
 are not familiar with Rack's basics, you should check out the [Resources](#resources)
@@ -122,9 +122,11 @@ use ActiveRecord::Migration::CheckPending
 use ActionDispatch::Cookies
 use ActionDispatch::Session::CookieStore
 use ActionDispatch::Flash
+use ActionDispatch::ContentSecurityPolicy::Middleware
 use Rack::Head
 use Rack::ConditionalGet
 use Rack::ETag
+use Rack::TempfileReaper
 run MyApp::Application.routes
 ```
 
@@ -132,7 +134,7 @@ The default middlewares shown here (and some others) are each summarized in the
 
 ### Configuring Middleware Stack
 
-Rails provides a simple configuration interface `config.middleware` for adding, removing and modifying the middlewares in the middleware stack via `application.rb` or the environment specific configuration file `environments/<environment>.rb`.
+Rails provides a simple configuration interface `config.middleware` for adding, removing, and modifying the middlewares in the middleware stack via `application.rb` or the environment specific configuration file `environments/<environment>.rb`.
 
 #### Adding a Middleware
 
@@ -249,7 +251,7 @@ Much of Action Controller's functionality is implemented as Middlewares. The fol
 
 **`Rails::Rack::Logger`**
 
-* Notifies the logs that the request has began. After request is complete, flushes all the logs.
+* Notifies the logs that the request has begun. After the request is complete, flushes all the logs.
 
 **`ActionDispatch::ShowExceptions`**
 
@@ -283,18 +285,26 @@ Much of Action Controller's functionality is implemented as Middlewares. The fol
 
 * Sets up the flash keys. Only available if `config.action_controller.session_store` is set to a value.
 
+**`ActionDispatch::ContentSecurityPolicy::Middleware`**
+
+* Provides a DSL to configure a Content-Security-Policy header.
+
 **`Rack::Head`**
 
 * Converts HEAD requests to `GET` requests and serves them as so.
 
 **`Rack::ConditionalGet`**
 
-* Adds support for "Conditional `GET`" so that server responds with nothing if page wasn't changed.
+* Adds support for "Conditional `GET`" so that server responds with nothing if the page wasn't changed.
 
 **`Rack::ETag`**
 
 * Adds ETag header on all String bodies. ETags are used to validate cache.
 
+**`Rack::TempfileReaper`**
+
+* Cleans up tempfiles used to buffer multipart requests.
+
 TIP: It's possible to use any of the above middlewares in your custom Rack stack.
 
 Resources