diff --git a/source/_components/input_select.markdown b/source/_components/input_select.markdown
index 45dbc19c0d8..d41555c13ab 100644
--- a/source/_components/input_select.markdown
+++ b/source/_components/input_select.markdown
@@ -43,6 +43,10 @@ Configuration variables:
 
 Pick an icon that you can find on [materialdesignicons.com](https://materialdesignicons.com/) to use for your input and prefix the name with `mdi:`. For example `mdi:car`, `mdi:ambulance`, or  `mdi:motorbike`.
 
+<p class='note'>
+Because YAML defines [booleans](http://yaml.org/type/bool.html) as equivalent, any variations of 'On', 'Yes', 'Y', 'Off', 'No', or 'N'  (regardless of case) used as option names will be replaced by True and False unless they are defined in quotation marks.
+</p>
+
 ### {% linkable_title Services %}
 
 This components provide three services to modify the state of the `input_select`: