There is an unsaved comment in progress. You will lose your changes if you continue. Are you sure you want to reopen the work item?
Page 11 says "Some XAML elements use a TargetType attribute to specify the type of element being referenced. For example, Styles use TargetType to specify the type of element being styled. WPF requires a more verbose nomenclature than Silverlight"
ACtually, TargetType="Button" works both in WPF and Silverlight.