6 files changed, 24 insertions, 4 deletions

diff --git a/guides/source/6_0_release_notes.md b/guides/source/6_0_release_notes.md
index c826b19f1a..c152076628 100644
--- a/guides/source/6_0_release_notes.md
+++ b/guides/source/6_0_release_notes.md
@@ -513,7 +513,7 @@ Please refer to the [Changelog][active-record] for detailed changes.
     ([Pull Request](https://github.com/rails/rails/pull/34742))
 
 *   Add the ability to disable scopes generated by `ActiveRecord.enum`.
-    ([Pull Request](https://github.com/rails/rails/pull/34605/files))
+    ([Pull Request](https://github.com/rails/rails/pull/34605))
 
 *   Make implicit ordering configurable for a column.
     ([Pull Request](https://github.com/rails/rails/pull/34480))
diff --git a/guides/source/configuring.md b/guides/source/configuring.md
index ffff9417b9..e53e8b4e92 100644
--- a/guides/source/configuring.md
+++ b/guides/source/configuring.md
@@ -1541,7 +1541,7 @@ Disallow: /
 ```
 
 To block just specific pages, it's necessary to use a more complex syntax. Learn
-it on the [official documentation](http://www.robotstxt.org/robotstxt.html).
+it on the [official documentation](https://www.robotstxt.org/robotstxt.html).
 
 Evented File System Monitor
 ---------------------------
diff --git a/guides/source/getting_started.md b/guides/source/getting_started.md
index 64f4a3b6b3..ce45dbb2a7 100644
--- a/guides/source/getting_started.md
+++ b/guides/source/getting_started.md
@@ -28,7 +28,7 @@ curve diving straight into Rails. There are several curated lists of online reso
 for learning Ruby:
 
 * [Official Ruby Programming Language website](https://www.ruby-lang.org/en/documentation/)
-* [List of Free Programming Books](https://github.com/vhf/free-programming-books/blob/master/free-programming-books.md#ruby)
+* [List of Free Programming Books](https://github.com/EbookFoundation/free-programming-books/blob/master/free-programming-books.md#ruby)
 
 Be aware that some resources, while still excellent, cover versions of Ruby as old as
 1.6, and commonly 1.8, and will not include some syntax that you will see in day-to-day
diff --git a/guides/source/initialization.md b/guides/source/initialization.md
index c19b2cffc5..556c85cc0f 100644
--- a/guides/source/initialization.md
+++ b/guides/source/initialization.md
@@ -108,6 +108,8 @@ A standard Rails application depends on several gems, specifically:
 * activerecord
 * activestorage
 * activesupport
+* actionmailbox
+* actiontext
 * arel
 * builder
 * bundler
@@ -538,6 +540,8 @@ require "rails"
   action_mailer/railtie
   active_job/railtie
   action_cable/engine
+  action_mailbox/engine
+  action_text/engine
   rails/test_unit/railtie
   sprockets/railtie
 ).each do |railtie|
diff --git a/guides/source/security.md b/guides/source/security.md
index 22c122d4b9..5bb7a51524 100644
--- a/guides/source/security.md
+++ b/guides/source/security.md
@@ -1211,4 +1211,4 @@ The security landscape shifts and it is important to keep up to date, because mi
 * Subscribe to the Rails security [mailing list](https://groups.google.com/forum/#!forum/rubyonrails-security).
 * [Brakeman - Rails Security Scanner](https://brakemanscanner.org/) - To perform static security analysis for Rails applications.
 * [Keep up to date on the other application layers](http://secunia.com/) (they have a weekly newsletter, too).
-* A [good security blog](https://www.owasp.org) including the [Cross-Site scripting Cheat Sheet](https://www.owasp.org/index.php/DOM_based_XSS_Prevention_Cheat_Sheet).
+* A [good security blog](https://www.owasp.org) including the [Cross-Site scripting Cheat Sheet](https://github.com/OWASP/CheatSheetSeries/blob/master/cheatsheets/Cross_Site_Scripting_Prevention_Cheat_Sheet.md).
diff --git a/guides/source/upgrading_ruby_on_rails.md b/guides/source/upgrading_ruby_on_rails.md
index 54f014293d..4192063e9b 100644
--- a/guides/source/upgrading_ruby_on_rails.md
+++ b/guides/source/upgrading_ruby_on_rails.md
@@ -270,6 +270,16 @@ In that case, `app/models/concerns` is assumed to be a root directory (because i
 
 The `Concerns::` namespace worked with the classic autoloader as a side-effect of the implementation, but it was not really an intended behavior. An application using `Concerns::` needs to rename those classes and modules to be able to run in `zeitwerk` mode.
 
+#### Having `app` in the autoload paths
+
+Some projects want something like `app/api/base.rb` to define `API::Base`, and add `app` to the autoload paths to accomplish that in `classic` mode. Since Rails adds all subdirectories of `app` to the autoload paths automatically, we have another situation in which there are nested root directories, so that setup no longer works. Similar principle we explained above with `concerns`.
+
+If you want to keep that structure, you'll need to delete the subdirectory from the autoload paths in an initializer:
+
+```ruby
+ActiveSupport::Dependencies.autoload_paths.delete("#{Rails.root}/app/api")
+```
+
 #### Autoloaded Constants and Explicit Namespaces
 
 If a namespace is defined in a file, as `Hotel` is here:
@@ -391,6 +401,12 @@ To fix this, just remove the wildcards:
 config.autoload_paths << "#{config.root}/lib"
 ```
 
+#### Eager loading and autoloading are consistent
+
+In `classic` mode, if `app/models/foo.rb` defines `Bar`, you won't be able to autoload that file, but eager loading will work because it loads files recursively blindly. This can be a source of errors if you test things first eager loading, execution may fail later autoloading.
+
+In `zeitwerk` mode both loading modes are consistent, they fail and err in the same files.
+
 #### How to Use the Classic Autoloader in Rails 6
 
 Applications can load Rails 6 defaults and still use the classic autoloader by setting `config.autoloader` this way: