Rules about controllers

README.md

@@ -152,10 +152,13 @@ some configurations need to be applied in the `config/initializers/carrierwave.r
 * Keep the controllers skinny - they should only retrieve data for the
   view layer and shouldn't contain any business logic (all the
   business logic should naturally reside in the model).
+* Each controller action should call only one method other than an initial find or new.
+* Share no more than two instance variables between a controller and a view.
 
 ## Models
 
 * Introduce non-ActiveRecord model classes freely.
+* Name the models with meaningful but short names without abbreviations.
 
 ### ActiveRecord
 
@@ -188,11 +191,11 @@ create a custom validator file.
     end
     ```
 
+* All custom validators should be moved to a shared gem.
 * Use named scopes freely.
 * When a named scope with lambda and parameters becomes too complicated it is better to make a class method instead which 
 serves the same purpose of the named scope and returns and `ActiveRecord::Relation` object.
 
-
 ## Migrations
 
 * Keep the schema.rb under version control.