diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 973415c1866..83b95535e0c 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -27,6 +27,7 @@ A state can have several attributes that will help the frontend in displaying yo
  - `friendly_name`: this name will be used as the name of the device
  - `entity_picture`: this picture will be shown instead of the domain icon
  - `unit_of_measurement`: this will be appended to the state in the interface
+ - `hidden`: This is a suggestion to the frontend on if the state should be hidden
 
 These attributes are defined in [homeassistant.components](https://github.com/balloob/home-assistant/blob/master/homeassistant/components/__init__.py#L25).