Setting Inverses on has_many through assoication documentation issues

According to the documentation

inverse_of as of rails 4.1 should work for anything except polymorphic associations.

The documentation at

http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html#module-ActiveRecord::Associations::ClassMethods-label-Setting+Inverses

Is very confusing. I believe inverse_of is still not working on has_many :through associations.

e.g.

class User < ActiveRecord::Base

has_many :attendances

has_many :events, through: :attendances

class Event < ActiveRecord::Base

has_many :attendances

has_many :users, through: :attendance

class Attendance < ActiveRecord::Base

belongs_to :event

belongs_to :user

No matter what inverse_of i set this doesn’t work. Also in the documentation the example isn’t complete enough to follow i.e. where is :taggings coming from?