Index: /trunk/src/VBox/Main/idl/VirtualBox.xidl
===================================================================
--- /trunk/src/VBox/Main/idl/VirtualBox.xidl	(revision 67894)
+++ /trunk/src/VBox/Main/idl/VirtualBox.xidl	(revision 67895)
@@ -3841,5 +3841,6 @@
       <desc>
         The image index on installation CD/DVD used to install.
-        Used only with Windows installation CD/DVD
+        Used only with Windows installation CD/DVD:
+        https://technet.microsoft.com/en-us/library/cc766022%28v=ws.10%29.aspx
       </desc>
     </attribute>