diff --git a/actionpack/lib/abstract_controller/base.rb b/actionpack/lib/abstract_controller/base.rb
index f357412fa5..16666cabf7 100644
--- a/actionpack/lib/abstract_controller/base.rb
+++ b/actionpack/lib/abstract_controller/base.rb
@@ -26,6 +26,8 @@ def corrections # :nodoc:
     end
   end
 
+  # = AbstractController \Base
+  #
   # AbstractController::Base is a low-level API. Nobody should be
   # using it directly, and subclasses (like ActionController::Base) are
   # expected to provide their own +render+ method, since rendering means
diff --git a/actionpack/lib/abstract_controller/caching/fragments.rb b/actionpack/lib/abstract_controller/caching/fragments.rb
index 4b0881814b..96532e8cb9 100644
--- a/actionpack/lib/abstract_controller/caching/fragments.rb
+++ b/actionpack/lib/abstract_controller/caching/fragments.rb
@@ -2,6 +2,8 @@
 
 module AbstractController
   module Caching
+    # = AbstractController Caching \Fragments
+    #
     # Fragment caching is used for caching various blocks within
     # views without caching the entire action as a whole. This is
     # useful when certain elements of an action change frequently or
diff --git a/actionpack/lib/action_controller/api.rb b/actionpack/lib/action_controller/api.rb
index 269116f624..b1d1be4c9f 100644
--- a/actionpack/lib/action_controller/api.rb
+++ b/actionpack/lib/action_controller/api.rb
@@ -5,6 +5,8 @@
 require "action_controller/log_subscriber"
 
 module ActionController
+  # = Action \Controller \Base
+  #
   # API Controller is a lightweight version of ActionController::Base,
   # created for applications that don't require all functionalities that a complete
   # \Rails controller provides, allowing you to create controllers with just the
diff --git a/actionpack/lib/action_controller/base.rb b/actionpack/lib/action_controller/base.rb
index ab4519789e..da148ce903 100644
--- a/actionpack/lib/action_controller/base.rb
+++ b/actionpack/lib/action_controller/base.rb
@@ -5,6 +5,8 @@
 require "action_controller/metal/params_wrapper"
 
 module ActionController
+  # = Action Controller \Base
+  #
   # Action Controllers are the core of a web request in \Rails. They are made up of one or more actions that are executed
   # on request and then either it renders a template or redirects to another action. An action is defined as a public method
   # on the controller, which will automatically be made accessible to the web-server through \Rails Routes.
diff --git a/actionpack/lib/action_controller/caching.rb b/actionpack/lib/action_controller/caching.rb
index 7a34911e9d..fd6869e175 100644
--- a/actionpack/lib/action_controller/caching.rb
+++ b/actionpack/lib/action_controller/caching.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 module ActionController
+  # = Action Controller \Caching
+  #
   # \Caching is a cheap way of speeding up slow applications by keeping the result of
   # calculations, renderings, and database calls around for subsequent requests.
   #
diff --git a/actionpack/lib/action_controller/form_builder.rb b/actionpack/lib/action_controller/form_builder.rb
index 19361d3db4..b9888a58d8 100644
--- a/actionpack/lib/action_controller/form_builder.rb
+++ b/actionpack/lib/action_controller/form_builder.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 module ActionController
+  # = Action Controller Form Builder
+  #
   # Override the default form builder for all views rendered by this
   # controller and any of its descendants. Accepts a subclass of
   # ActionView::Helpers::FormBuilder.
diff --git a/actionpack/lib/action_controller/metal.rb b/actionpack/lib/action_controller/metal.rb
index aec1124b09..1d4f0a8988 100644
--- a/actionpack/lib/action_controller/metal.rb
+++ b/actionpack/lib/action_controller/metal.rb
@@ -4,6 +4,8 @@
 require "action_dispatch/middleware/stack"
 
 module ActionController
+  # = Action Controller \MiddlewareStack
+  #
   # Extend ActionDispatch middleware stack to make it aware of options
   # allowing the following syntax in controllers:
   #
@@ -58,6 +60,8 @@ def build_middleware(klass, args, block)
       end
   end
 
+  # = Action Controller \Metal
+  #
   # <tt>ActionController::Metal</tt> is the simplest possible controller, providing a
   # valid Rack interface without the additional niceties provided by
   # ActionController::Base.
diff --git a/actionpack/lib/action_controller/metal/data_streaming.rb b/actionpack/lib/action_controller/metal/data_streaming.rb
index 89b8dde84f..3962c8c926 100644
--- a/actionpack/lib/action_controller/metal/data_streaming.rb
+++ b/actionpack/lib/action_controller/metal/data_streaming.rb
@@ -4,6 +4,8 @@
 require "action_dispatch/http/content_disposition"
 
 module ActionController # :nodoc:
+  # = Action Controller Data Streaming
+  #
   # Methods for sending arbitrary data and for streaming files to the browser,
   # instead of rendering.
   module DataStreaming
diff --git a/actionpack/lib/action_controller/metal/default_headers.rb b/actionpack/lib/action_controller/metal/default_headers.rb
index eef0602fcd..c7bee2259f 100644
--- a/actionpack/lib/action_controller/metal/default_headers.rb
+++ b/actionpack/lib/action_controller/metal/default_headers.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 module ActionController
+  # = Action Controller Default Headers
+  #
   # Allows configuring default headers that will be automatically merged into
   # each response.
   module DefaultHeaders
diff --git a/actionpack/lib/action_controller/metal/etag_with_flash.rb b/actionpack/lib/action_controller/metal/etag_with_flash.rb
index ff36009f02..7434cd2a51 100644
--- a/actionpack/lib/action_controller/metal/etag_with_flash.rb
+++ b/actionpack/lib/action_controller/metal/etag_with_flash.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 module ActionController
+  # = Action Controller Etag With Flash
+  #
   # When you're using the flash, it's generally used as a conditional on the view.
   # This means the content of the view depends on the flash. Which in turn means
   # that the ETag for a response should be computed with the content of the flash
diff --git a/actionpack/lib/action_controller/metal/etag_with_template_digest.rb b/actionpack/lib/action_controller/metal/etag_with_template_digest.rb
index 6607ed009e..e33c4f4e78 100644
--- a/actionpack/lib/action_controller/metal/etag_with_template_digest.rb
+++ b/actionpack/lib/action_controller/metal/etag_with_template_digest.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 module ActionController
+  # = Action Controller Etag With Template Digest
+  #
   # When our views change, they should bubble up into HTTP cache freshness
   # and bust browser caches. So the template digest for the current action
   # is automatically included in the ETag.
diff --git a/actionpack/lib/action_controller/metal/implicit_render.rb b/actionpack/lib/action_controller/metal/implicit_render.rb
index 263314f3c2..a10885c71b 100644
--- a/actionpack/lib/action_controller/metal/implicit_render.rb
+++ b/actionpack/lib/action_controller/metal/implicit_render.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 module ActionController
+  # = Action Controller Implicit Render
+  #
   # Handles implicit rendering for a controller action that does not
   # explicitly respond with +render+, +respond_to+, +redirect+, or +head+.
   #
diff --git a/actionpack/lib/action_controller/metal/instrumentation.rb b/actionpack/lib/action_controller/metal/instrumentation.rb
index babb0e51e5..43ebc120c5 100644
--- a/actionpack/lib/action_controller/metal/instrumentation.rb
+++ b/actionpack/lib/action_controller/metal/instrumentation.rb
@@ -4,6 +4,8 @@
 require "abstract_controller/logger"
 
 module ActionController
+  # = Action Controller \Instrumentation
+  #
   # Adds instrumentation to several ends in ActionController::Base. It also provides
   # some hooks related with process_action. This allows an ORM like Active Record
   # and/or DataMapper to plug in ActionController and show related information.
diff --git a/actionpack/lib/action_controller/metal/live.rb b/actionpack/lib/action_controller/metal/live.rb
index 95fc557058..73ccaadd5e 100644
--- a/actionpack/lib/action_controller/metal/live.rb
+++ b/actionpack/lib/action_controller/metal/live.rb
@@ -5,6 +5,8 @@
 require "active_support/json"
 
 module ActionController
+  # = Action  Controller \Live
+  #
   # Mix this module into your controller, and all actions in that controller
   # will be able to stream data to the client as it's written.
   #
diff --git a/actionpack/lib/action_controller/metal/params_wrapper.rb b/actionpack/lib/action_controller/metal/params_wrapper.rb
index 00d5e82f7b..2074c32dd9 100644
--- a/actionpack/lib/action_controller/metal/params_wrapper.rb
+++ b/actionpack/lib/action_controller/metal/params_wrapper.rb
@@ -6,6 +6,8 @@
 require "action_dispatch/http/mime_type"
 
 module ActionController
+  # = Action Controller Params Wrapper
+  #
   # Wraps the parameters hash into a nested hash. This will allow clients to
   # submit requests without having to specify any root elements.
   #
diff --git a/actionpack/lib/action_controller/metal/request_forgery_protection.rb b/actionpack/lib/action_controller/metal/request_forgery_protection.rb
index 0adec1ac8f..35de8d3366 100644
--- a/actionpack/lib/action_controller/metal/request_forgery_protection.rb
+++ b/actionpack/lib/action_controller/metal/request_forgery_protection.rb
@@ -11,6 +11,8 @@ class InvalidAuthenticityToken < ActionControllerError # :nodoc:
   class InvalidCrossOriginRequest < ActionControllerError # :nodoc:
   end
 
+  # = Action Controller Request Forgery Protection
+  #
   # Controller actions are protected from Cross-Site Request Forgery (CSRF) attacks
   # by including a token in the rendered HTML for your application. This token is
   # stored as a random string in the session, to which an attacker does not have
diff --git a/actionpack/lib/action_controller/metal/rescue.rb b/actionpack/lib/action_controller/metal/rescue.rb
index b1e4e3d400..950d20ed1a 100644
--- a/actionpack/lib/action_controller/metal/rescue.rb
+++ b/actionpack/lib/action_controller/metal/rescue.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 module ActionController # :nodoc:
+  # = Action Controller \Rescue
+  #
   # This module is responsible for providing +rescue_from+ helpers
   # to controllers and configuring when detailed exceptions must be
   # shown.
diff --git a/actionpack/lib/action_controller/metal/streaming.rb b/actionpack/lib/action_controller/metal/streaming.rb
index 60136caf4d..d2e92c57d0 100644
--- a/actionpack/lib/action_controller/metal/streaming.rb
+++ b/actionpack/lib/action_controller/metal/streaming.rb
@@ -3,6 +3,8 @@
 require "rack/chunked"
 
 module ActionController # :nodoc:
+  # = Action Controller \Streaming
+  #
   # Allows views to be streamed back to the client as they are rendered.
   #
   # By default, Rails renders views by first rendering the template
diff --git a/actionpack/lib/action_controller/metal/url_for.rb b/actionpack/lib/action_controller/metal/url_for.rb
index 1acb67219d..a9b2770571 100644
--- a/actionpack/lib/action_controller/metal/url_for.rb
+++ b/actionpack/lib/action_controller/metal/url_for.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 module ActionController
+  # = Action Controller \UrlFor
+  #
   # Includes +url_for+ into the host class. The class has to provide a +RouteSet+ by implementing
   # the <tt>_routes</tt> method. Otherwise, an exception will be raised.
   #
diff --git a/actionpack/lib/action_controller/renderer.rb b/actionpack/lib/action_controller/renderer.rb
index 157fe4b63c..c15ac5ad7f 100644
--- a/actionpack/lib/action_controller/renderer.rb
+++ b/actionpack/lib/action_controller/renderer.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 module ActionController
+  # = Action Controller \Renderer
+  #
   # ActionController::Renderer allows you to render arbitrary templates without
   # being inside a controller action.
   #
diff --git a/actionpack/lib/action_dispatch/http/content_security_policy.rb b/actionpack/lib/action_dispatch/http/content_security_policy.rb
index 135d10436b..fa13ee8617 100644
--- a/actionpack/lib/action_dispatch/http/content_security_policy.rb
+++ b/actionpack/lib/action_dispatch/http/content_security_policy.rb
@@ -4,6 +4,8 @@
 require "active_support/core_ext/array/wrap"
 
 module ActionDispatch # :nodoc:
+  # = Action Dispatch Content Security Policy
+  #
   # Configures the HTTP
   # {Content-Security-Policy}[https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy]
   # response header to help protect against XSS and injection attacks.
diff --git a/actionpack/lib/action_dispatch/http/filter_parameters.rb b/actionpack/lib/action_dispatch/http/filter_parameters.rb
index fc40b96401..54ba0ec7b8 100644
--- a/actionpack/lib/action_dispatch/http/filter_parameters.rb
+++ b/actionpack/lib/action_dispatch/http/filter_parameters.rb
@@ -4,6 +4,8 @@
 
 module ActionDispatch
   module Http
+    # = Action Dispatch HTTP Filter Parameters
+    #
     # Allows you to specify sensitive query string and POST parameters to filter
     # from the request log.
     #
diff --git a/actionpack/lib/action_dispatch/http/headers.rb b/actionpack/lib/action_dispatch/http/headers.rb
index 2a05c04466..d9bd5da2b1 100644
--- a/actionpack/lib/action_dispatch/http/headers.rb
+++ b/actionpack/lib/action_dispatch/http/headers.rb
@@ -2,6 +2,8 @@
 
 module ActionDispatch
   module Http
+    # = Action Dispatch HTTP \Headers
+    #
     # Provides access to the request's HTTP headers from the environment.
     #
     #   env     = { "CONTENT_TYPE" => "text/plain", "HTTP_USER_AGENT" => "curl/7.43.0" }
diff --git a/actionpack/lib/action_dispatch/http/permissions_policy.rb b/actionpack/lib/action_dispatch/http/permissions_policy.rb
index 96a9df9a11..badf7c5343 100644
--- a/actionpack/lib/action_dispatch/http/permissions_policy.rb
+++ b/actionpack/lib/action_dispatch/http/permissions_policy.rb
@@ -3,6 +3,8 @@
 require "active_support/core_ext/object/deep_dup"
 
 module ActionDispatch # :nodoc:
+  # = Action Dispatch \PermissionsPolicy
+  #
   # Configures the HTTP
   # {Feature-Policy}[https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Feature-Policy]
   # response header to specify which browser features the current document and
diff --git a/actionpack/lib/action_dispatch/http/response.rb b/actionpack/lib/action_dispatch/http/response.rb
index 7e7cb4bac3..b962082e11 100644
--- a/actionpack/lib/action_dispatch/http/response.rb
+++ b/actionpack/lib/action_dispatch/http/response.rb
@@ -6,6 +6,8 @@
 require "monitor"
 
 module ActionDispatch # :nodoc:
+  # = Action Dispatch \Response
+  #
   # Represents an HTTP response generated by a controller action. Use it to
   # retrieve the current state of the response, or customize the response. It can
   # either represent a real HTTP response (i.e. one that is meant to be sent
diff --git a/actionpack/lib/action_dispatch/http/upload.rb b/actionpack/lib/action_dispatch/http/upload.rb
index 7f5b796d21..60d4d72c08 100644
--- a/actionpack/lib/action_dispatch/http/upload.rb
+++ b/actionpack/lib/action_dispatch/http/upload.rb
@@ -2,6 +2,8 @@
 
 module ActionDispatch
   module Http
+    # = Action Dispatch HTTP \UploadedFile
+    #
     # Models uploaded files.
     #
     # The actual file is accessible via the +tempfile+ accessor, though some
diff --git a/actionpack/lib/action_dispatch/middleware/assume_ssl.rb b/actionpack/lib/action_dispatch/middleware/assume_ssl.rb
index da1ada526b..6a525de9df 100644
--- a/actionpack/lib/action_dispatch/middleware/assume_ssl.rb
+++ b/actionpack/lib/action_dispatch/middleware/assume_ssl.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 module ActionDispatch
+  # = Action Dispatch \AssumeSSL
+  #
   # When proxying through a load balancer that terminates SSL, the forwarded request will appear
   # as though its HTTP instead of HTTPS to the application. This makes redirects and cookie
   # security target HTTP instead of HTTPS. This middleware makes the server assume that the
diff --git a/actionpack/lib/action_dispatch/middleware/callbacks.rb b/actionpack/lib/action_dispatch/middleware/callbacks.rb
index 87fe19225b..4d58f37941 100644
--- a/actionpack/lib/action_dispatch/middleware/callbacks.rb
+++ b/actionpack/lib/action_dispatch/middleware/callbacks.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 module ActionDispatch
+  # = Action Dispatch \Callbacks
+  #
   # Provides callbacks to be executed before and after dispatching the request.
   class Callbacks
     include ActiveSupport::Callbacks
diff --git a/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb b/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
index 918ed5fd9d..4cf30677b1 100644
--- a/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
+++ b/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
@@ -6,6 +6,8 @@
 require "action_view"
 
 module ActionDispatch
+  # = Action Dispatch \DebugExceptions
+  #
   # This middleware is responsible for logging exceptions and
   # showing a debugging page in case the request is local.
   class DebugExceptions
diff --git a/actionpack/lib/action_dispatch/middleware/debug_locks.rb b/actionpack/lib/action_dispatch/middleware/debug_locks.rb
index af3a274ea1..323bc9bd71 100644
--- a/actionpack/lib/action_dispatch/middleware/debug_locks.rb
+++ b/actionpack/lib/action_dispatch/middleware/debug_locks.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 module ActionDispatch
+  # = Action Dispatch \DebugLocks
+  #
   # This middleware can be used to diagnose deadlocks in the autoload interlock.
   #
   # To use it, insert it near the top of the middleware stack, using
diff --git a/actionpack/lib/action_dispatch/middleware/flash.rb b/actionpack/lib/action_dispatch/middleware/flash.rb
index 6eb2983d3a..f0bc8d5242 100644
--- a/actionpack/lib/action_dispatch/middleware/flash.rb
+++ b/actionpack/lib/action_dispatch/middleware/flash.rb
@@ -3,6 +3,8 @@
 require "active_support/core_ext/hash/keys"
 
 module ActionDispatch
+  # = Action Dispatch \Flash
+  #
   # The flash provides a way to pass temporary primitive-types (String, Array, Hash) between actions. Anything you place in the flash will be exposed
   # to the very next action and then cleared out. This is a great way of doing notices and alerts, such as a create
   # action that sets <tt>flash[:notice] = "Post successfully created"</tt> before redirecting to a display action that can
diff --git a/actionpack/lib/action_dispatch/middleware/host_authorization.rb b/actionpack/lib/action_dispatch/middleware/host_authorization.rb
index 5121060a1c..7d694b3ea9 100644
--- a/actionpack/lib/action_dispatch/middleware/host_authorization.rb
+++ b/actionpack/lib/action_dispatch/middleware/host_authorization.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 module ActionDispatch
+  # = Action Dispatch \HostAuthorization
+  #
   # This middleware guards from DNS rebinding attacks by explicitly permitting
   # the hosts a request can be sent to, and is passed the options set in
   # +config.host_authorization+.
diff --git a/actionpack/lib/action_dispatch/middleware/public_exceptions.rb b/actionpack/lib/action_dispatch/middleware/public_exceptions.rb
index 4404dbe874..66356d0d24 100644
--- a/actionpack/lib/action_dispatch/middleware/public_exceptions.rb
+++ b/actionpack/lib/action_dispatch/middleware/public_exceptions.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 module ActionDispatch
+  # = ActionDispatch \PublicExceptions
+  #
   # When called, this middleware renders an error page. By default if an HTML
   # response is expected it will render static error pages from the <tt>/public</tt>
   # directory. For example when this middleware receives a 500 response it will
diff --git a/actionpack/lib/action_dispatch/middleware/reloader.rb b/actionpack/lib/action_dispatch/middleware/reloader.rb
index 6eba084bb8..0cf5d55f29 100644
--- a/actionpack/lib/action_dispatch/middleware/reloader.rb
+++ b/actionpack/lib/action_dispatch/middleware/reloader.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 module ActionDispatch
+  # = Action Dispatch \Reloader
+  #
   # ActionDispatch::Reloader wraps the request with callbacks provided by
   # ActiveSupport::Reloader, intended to assist with code reloading during
   # development.
diff --git a/actionpack/lib/action_dispatch/middleware/remote_ip.rb b/actionpack/lib/action_dispatch/middleware/remote_ip.rb
index 83c7a78006..bc06ba62e5 100644
--- a/actionpack/lib/action_dispatch/middleware/remote_ip.rb
+++ b/actionpack/lib/action_dispatch/middleware/remote_ip.rb
@@ -3,6 +3,8 @@
 require "ipaddr"
 
 module ActionDispatch
+  # = Action Dispatch \RemoteIp
+  #
   # This middleware calculates the IP address of the remote client that is
   # making the request. It does this by checking various headers that could
   # contain the address, and then picking the last-set address that is not
diff --git a/actionpack/lib/action_dispatch/middleware/request_id.rb b/actionpack/lib/action_dispatch/middleware/request_id.rb
index 8e833d0d22..42db8a5988 100644
--- a/actionpack/lib/action_dispatch/middleware/request_id.rb
+++ b/actionpack/lib/action_dispatch/middleware/request_id.rb
@@ -4,6 +4,8 @@
 require "active_support/core_ext/string/access"
 
 module ActionDispatch
+  # = Action Dispatch \RequestId
+  #
   # Makes a unique request id available to the +action_dispatch.request_id+ env variable (which is then accessible
   # through ActionDispatch::Request#request_id or the alias ActionDispatch::Request#uuid) and sends
   # the same id to the client via the +X-Request-Id+ header.
diff --git a/actionpack/lib/action_dispatch/middleware/session/cache_store.rb b/actionpack/lib/action_dispatch/middleware/session/cache_store.rb
index c7b61f96ef..d76c3a6b70 100644
--- a/actionpack/lib/action_dispatch/middleware/session/cache_store.rb
+++ b/actionpack/lib/action_dispatch/middleware/session/cache_store.rb
@@ -4,6 +4,8 @@
 
 module ActionDispatch
   module Session
+    # = Action Dispatch Session \CacheStore
+    #
     # A session store that uses an ActiveSupport::Cache::Store to store the sessions. This store is most useful
     # if you don't store critical data in your sessions and you don't need them to live for extended periods
     # of time.
diff --git a/actionpack/lib/action_dispatch/middleware/session/cookie_store.rb b/actionpack/lib/action_dispatch/middleware/session/cookie_store.rb
index 9fde5e0da4..dc4b0174da 100644
--- a/actionpack/lib/action_dispatch/middleware/session/cookie_store.rb
+++ b/actionpack/lib/action_dispatch/middleware/session/cookie_store.rb
@@ -6,6 +6,8 @@
 
 module ActionDispatch
   module Session
+    # = ActionDispatch Session \CookieStore
+    #
     # This cookie-based session store is the Rails default. It is
     # dramatically faster than the alternatives.
     #
diff --git a/actionpack/lib/action_dispatch/middleware/session/mem_cache_store.rb b/actionpack/lib/action_dispatch/middleware/session/mem_cache_store.rb
index 914df3a2b1..f0cb7f0189 100644
--- a/actionpack/lib/action_dispatch/middleware/session/mem_cache_store.rb
+++ b/actionpack/lib/action_dispatch/middleware/session/mem_cache_store.rb
@@ -10,6 +10,8 @@
 
 module ActionDispatch
   module Session
+    # = Action Dispatch Session \MemCacheStore
+    #
     # A session store that uses MemCache to implement storage.
     #
     # ==== Options
diff --git a/actionpack/lib/action_dispatch/middleware/show_exceptions.rb b/actionpack/lib/action_dispatch/middleware/show_exceptions.rb
index 69a8fa4fbf..013422e260 100644
--- a/actionpack/lib/action_dispatch/middleware/show_exceptions.rb
+++ b/actionpack/lib/action_dispatch/middleware/show_exceptions.rb
@@ -3,6 +3,8 @@
 require "action_dispatch/middleware/exception_wrapper"
 
 module ActionDispatch
+  # = Action Dispatch \ShowExceptions
+  #
   # This middleware rescues any exception returned by the application
   # and calls an exceptions app that will wrap it in a format for the end user.
   #
diff --git a/actionpack/lib/action_dispatch/middleware/ssl.rb b/actionpack/lib/action_dispatch/middleware/ssl.rb
index 2bb02932d7..9788aaadd9 100644
--- a/actionpack/lib/action_dispatch/middleware/ssl.rb
+++ b/actionpack/lib/action_dispatch/middleware/ssl.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 module ActionDispatch
+  # = Action Dispatch \SSL
+  #
   # This middleware is added to the stack when <tt>config.force_ssl = true</tt>, and is passed
   # the options set in +config.ssl_options+. It does three jobs to enforce secure HTTP
   # requests:
diff --git a/actionpack/lib/action_dispatch/middleware/static.rb b/actionpack/lib/action_dispatch/middleware/static.rb
index 854fe826f6..17ef88a2bf 100644
--- a/actionpack/lib/action_dispatch/middleware/static.rb
+++ b/actionpack/lib/action_dispatch/middleware/static.rb
@@ -3,6 +3,8 @@
 require "rack/utils"
 
 module ActionDispatch
+  # = Action Dispatch \Static
+  #
   # This middleware serves static files from disk, if available.
   # If no file is found, it hands off to the main app.
   #
@@ -24,6 +26,8 @@ def call(env)
     end
   end
 
+  # = ActionDispatch \FileHandler
+  #
   # This endpoint serves static files from disk using +Rack::Files+.
   #
   # URL paths are matched with static files according to expected
diff --git a/actionpack/lib/action_dispatch/routing/polymorphic_routes.rb b/actionpack/lib/action_dispatch/routing/polymorphic_routes.rb
index 77499bf157..b92e02e2ca 100644
--- a/actionpack/lib/action_dispatch/routing/polymorphic_routes.rb
+++ b/actionpack/lib/action_dispatch/routing/polymorphic_routes.rb
@@ -2,6 +2,8 @@
 
 module ActionDispatch
   module Routing
+    # = Action Dispatch Routing \PolymorphicRoutes
+    #
     # Polymorphic URL helpers are methods for smart resolution to a named route call when
     # given an Active Record model instance. They are to be used in combination with
     # ActionController::Resources.
diff --git a/actionpack/lib/action_dispatch/routing/url_for.rb b/actionpack/lib/action_dispatch/routing/url_for.rb
index 9d52f000d5..bfc3935b65 100644
--- a/actionpack/lib/action_dispatch/routing/url_for.rb
+++ b/actionpack/lib/action_dispatch/routing/url_for.rb
@@ -2,6 +2,8 @@
 
 module ActionDispatch
   module Routing
+    # = Action Dispatch Routing \UrlFor
+    #
     # In <tt>config/routes.rb</tt> you define URL-to-controller mappings, but the reverse
     # is also possible: a URL can be generated from one of your routing definitions.
     # URL generation functionality is centralized in this module.