Clarify Bi-directional Associations docs

Rails automatically finds bi-directional associations between models
with well-named associations. However, when using non-standard naming,
you have to use :inverse_of to explicitly tell Rails about the bi-
directional association.

With reference to #27516

[ci skip]

guides/source/association_basics.md

@@ -709,56 +709,74 @@ class Book < ApplicationRecord
 end
 ```
 
-By default, Active Record doesn't know about the connection between these associations. This can lead to two copies of an object getting out of sync:
+Active Record will attempt to automatically identify that these two models share a bi-directional association based on the association name. In this way, Active Record will only load one copy of the `Author` object, making your application more efficient and preventing inconsistent data:
 
 ```ruby
 a = Author.first
 b = a.books.first
 a.first_name == b.author.first_name # => true
-a.first_name = 'Manny'
-a.first_name == b.author.first_name # => false
-```
-
-This happens because `a` and `b.author` are two different in-memory representations of the same data, and neither one is automatically refreshed from changes to the other. Active Record provides the `:inverse_of` option so that you can inform it of these relations:
-
-```ruby
-class Author < ApplicationRecord
-  has_many :books, inverse_of: :author
-end
-
-class Book < ApplicationRecord
-  belongs_to :author, inverse_of: :books
-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
-b = a.books.first
-a.first_name == b.author.first_name # => true
-a.first_name = 'Manny'
+a.first_name = 'David'
 a.first_name == b.author.first_name # => true
 ```
 
-There are a few limitations to `inverse_of` support:
-
-* They do not work with `:through` associations.
-* They do not work with `:polymorphic` associations.
-* They do not work with `:as` associations.
-* For `belongs_to` associations, `has_many` inverse associations are ignored.
-
-Every association will attempt to automatically find the inverse association
-and set the `:inverse_of` option heuristically (based on the association name).
-Most associations with standard names will be supported. However, associations
-that contain the following options will not have their inverses set
-automatically:
+Active Record supports automatic identification for most associations with standard names. However, Active Record will not automatically identify bi-directional associations that contain any of the following options:
 
 * `:conditions`
 * `:through`
 * `:polymorphic`
+* `:class_name`
 * `:foreign_key`
 
+For example, consider the following model declarations:
+
+```ruby
+class Author < ApplicationRecord
+  has_many :books
+end
+
+class Book < ApplicationRecord
+  belongs_to :writer, class_name: 'Author', foreign_key: 'author_id'
+end
+```
+
+Active Record will no longer automatically recognize the bi-directional association:
+
+```ruby
+a = Author.first
+b = a.books.first
+a.first_name == b.writer.first_name # => true
+a.first_name = 'David'
+a.first_name == b.writer.first_name # => false
+```
+
+Active Record provides the `:inverse_of` option so you can explicitly declare bi-directional associations:
+
+```ruby
+class Author < ApplicationRecord
+  has_many :books, inverse_of: 'writer'
+end
+
+class Book < ApplicationRecord
+  belongs_to :writer, class_name: 'Author', foreign_key: 'author_id'
+end
+```
+
+By including the `:inverse_of` option in the `has_many` association declaration, Active Record will now recognize the bi-directional association:
+
+```ruby
+a = Author.first
+b = a.books.first
+a.first_name == b.writer.first_name # => true
+a.first_name = 'David'
+a.first_name == b.writer.first_name # => true
+```
+
+There are a few limitations to `:inverse_of` support:
+
+* They do not work with `:through` associations.
+* They do not work with `:polymorphic` associations.
+* They do not work with `:as` associations.
+
 Detailed Association Reference
 ------------------------------