README.md in rails_state_machine-2.1.1 vs README.md in rails_state_machine-2.2.0

@@ -105,25 +105,36 @@
 
 ## Other state attributes and multiple state machines on the same model
 
 To use a state attribute other than the default `state`, pass it to the `.state_machine` method:
 
-```
+```ruby
 state_machine :review_state do
   # ...
 end
 ```
 
 This also allows you to define multiple state machines on the same model. Note that event
 and state names still have to be unique for the whole model.
 
+If you define multiple state machines on the same model, and use state names more than once,
+you must use a prefix to avoid name collisions.
 
+A prefix may be specified by passing the `:prefix` option when declaring your state machine:
+
+```ruby
+state_machine :review_state, prefix: 'some_prefix' do
+  # ...
+end
+```
+
+
 ## Taking multiple transitions
 
 You can safely take a second transition inside an after_save callback. All relevant
 callbacks will be run.
 
-```
+```ruby
 state_machine do
   state :draft, initial: true
   state :review_pending
   state :approved