AR template

template.rb

class Example < ActiveRecord::Base
 ## includes
 ## plugins
 ## associations
 ## validations
 ## callbacks
 ## attr_*, delegate aliases, accepts_nested_attributes_for
 ## scopes
 ## class methods
 ## public methods
 ## protected methods
 ## private methods
end

Where does accepts_nested_attributes_for fit into?

Put it wherever you need it :) I think it fits good after callbacks since basically it creates public methods or maybe even in plugin section because feels like a plugin... This is just in order to prevent total mess up in models since everybody wants it his way :) Basically as you discuss it with your team.