Merged PR 20951: update description and remarks

update description and remarks

Author: jwmsft

windows.ui.xaml/applicationinitializationcallbackparams.md

@@ -10,14 +10,23 @@ public class ApplicationInitializationCallbackParams : Windows.UI.Xaml.IApplicat
 # Windows.UI.Xaml.ApplicationInitializationCallbackParams
 
 ## -description
-A class that developers should derive from in order to pass information for a custom initialization sequence, in cases where both an [Application](application.md) subclass is present and the entry point [Start](application_start_1074858869.md) call is adjusted to pass the information.
-
 
+Represents an object to pass information for a custom initialization sequence.
 
 ## -remarks
+
+In Windows 10 and later, this class is sealed.
+
+### Notes for previous versions
+
+> **Windows 8**
+
+You should derive from this class in order to pass information for a custom initialization sequence, in cases where both an [Application](application.md) subclass is present and the entry point [Start](application_start_1074858869.md) call is adjusted to pass the information.
+
 This class is used as a custom information source for an [ApplicationInitializationCallback](applicationinitializationcallback.md) implementation. The basic ApplicationInitializationCallbackParams does not have any unique members. Your subclass should add any members you need for initialization information.
 
 ## -examples
 
 ## -see-also
+
 [Application](application.md), [ApplicationInitializationCallback](applicationinitializationcallback.md)