diff --git a/actionpack/lib/action_controller/metal/parameter_encoding.rb b/actionpack/lib/action_controller/metal/parameter_encoding.rb
index f5d3dabb456ffc9b2efe222b1345a0275c09bc93..75d92087a8802395e8bbe47b35348ef0cb0bbaa5 100644
--- a/actionpack/lib/action_controller/metal/parameter_encoding.rb
+++ b/actionpack/lib/action_controller/metal/parameter_encoding.rb
@@ -1,4 +1,5 @@
 module ActionController
+  # Allows encoding to be specified per parameter per action.
   module ParameterEncoding
     extend ActiveSupport::Concern