diff --git a/src/Umbraco.Web.UI/config/umbracoSettings.Release.config b/src/Umbraco.Web.UI/config/umbracoSettings.Release.config
index b371f536e6..4c21cedd54 100644
--- a/src/Umbraco.Web.UI/config/umbracoSettings.Release.config
+++ b/src/Umbraco.Web.UI/config/umbracoSettings.Release.config
@@ -12,6 +12,12 @@
     
     <errors>
       <error404>1</error404>
+      <!-- 
+        The value for error pages can be:
+        * A content item's integer ID   (example: 1234)
+        * A content item's GUID ID      (example: 26C1D84F-C900-4D53-B167-E25CC489DAC8)
+        * An XPath statement            (example: //errorPages[@nodeName='My cool error']
+      -->
       <!--
         <error404>
             <errorPage culture="default">1</errorPage>