README.md in field_test-0.4.0 vs README.md in field_test-0.4.1

@@ -158,11 +158,11 @@
 ```ruby
 experiment = FieldTest::Experiment.find(:button_color)
 button_color = experiment.variant(user)
 ```
 
-## Config
+## Exclusions
 
 By default, bots are returned the first variant and excluded from metrics. Change this with:
 
 ```yml
 exclude:
@@ -175,9 +175,17 @@
 exclude:
   ips:
     - 127.0.0.1
     - 10.0.0.0/8
 ```
+
+You can also use custom logic:
+
+```ruby
+field_test(:button_color, exclude: request.user_agent == "Test")
+```
+
+## Config
 
 Keep track of when experiments started and ended. Use any format `Time.parse` accepts. Variants assigned outside this window are not included in metrics.
 
 ```yml
 experiments: