Missed changelog entry for :inverse_of

activerecord/CHANGELOG

 *Edge*
 
+* Association inverses for belongs_to, has_one, and has_many. Optimization to reduce database queries.  #3533 [Murray Steele]
+
+    # post.comments sets each comment's post without needing to :include
+    class Post < ActiveRecord::Base
+      has_many :comments, :inverse_of => :post
+    end
+
 * MySQL: add_ and change_column support positioning.  #3286 [Ben Marini]
 
 * Reset your Active Record counter caches with the reset_counter_cache class method.  #1211 [Mike Breen, Gabe da Silveira]