10.2 Object Node Constraints
The following is a constraint to add to section 4.2.1 of [MS-XAML]. Silverlight imposes the following additional constraint on setting xmlns values on an Object Node Information Item.
4.2.1.S1.If a default xmlns declaration is made on an Object Node Information Item, that default xmlns declaration MUST be one of the following: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/client/2007.