Setting for enabling inherited documenttypes.

src/Umbraco.Core/Configuration/UmbracoSettings/ContentElement.cs

@@ -280,6 +280,18 @@ namespace Umbraco.Core.Configuration.UmbracoSettings
             }
         }
 
+        [ConfigurationProperty("EnableInheritedDocumentTypes")]
+        internal InnerTextConfigurationElement<bool> EnableInheritedDocumentTypes
+        {
+            get
+            {
+                return new OptionalInnerTextConfigurationElement<bool>(
+                          (InnerTextConfigurationElement<bool>)this["EnableInheritedDocumentTypes"],
+                          //set the default
+                          true);
+            }
+        }
+        
         string IContentSection.NotificationEmailAddress
         {
             get { return Notifications.NotificationEmailAddress; }
@@ -414,5 +426,10 @@ namespace Umbraco.Core.Configuration.UmbracoSettings
         {
             get { return DefaultDocumentTypeProperty; }
         }
+
+        bool IContentSection.EnableInheritedDocumentTypes
+        {
+            get { return ContinouslyUpdateXmlDiskCache; }
+        }
     }
 }

src/Umbraco.Core/Configuration/UmbracoSettings/IContentSection.cs

@@ -59,5 +59,7 @@ namespace Umbraco.Core.Configuration.UmbracoSettings
         bool GlobalPreviewStorageEnabled { get; }
 
         string DefaultDocumentTypeProperty { get; }
+
+        bool EnableInheritedDocumentTypes { get; }
     }
 }

src/Umbraco.Web.UI/config/umbracoSettings.config

@@ -102,6 +102,9 @@
 
     <!-- Defines the default document type property used when adding properties in the back-office (if missing or empty, defaults to Textstring -->
     <defaultDocumentTypeProperty>Textstring</defaultDocumentTypeProperty>
+    
+    <!-- Enable inherited document types. This feature will be deprecated in v8 -->
+    <EnableInheritedDocumentTypes>true</EnableInheritedDocumentTypes>
   </content>
 
   <security>

src/umbraco.businesslogic/UmbracoSettings.cs

@@ -609,6 +609,17 @@ namespace umbraco
             get { return UmbracoConfig.For.UmbracoSettings().Content.DefaultDocumentTypeProperty; }
         }
 
+        /// <summary>
+        /// Enables inherited document types.
+        /// This feature is not recommended and therefore is not enabled by default in new installations.
+        /// Inherited document types will not be supported in v8.
+        /// </summary>
+        //[Obsolete("This will not be supported in v8")]
+        public static bool EnableInheritedDocumentTypes
+        {
+            get { return UmbracoConfig.For.UmbracoSettings().Content.EnableInheritedDocumentTypes; }
+        }
+
         private static string _path;
 
         /// <summary>