Update appcapability_displaymessage.md

Author: jeffreywang-ms

windows.security.authorization.appcapabilityaccess/appcapability_displaymessage.md

@@ -17,7 +17,7 @@ The purpose of why the capability is being accessed.
 The stored display message as a string property.
 
 ## -remarks
-The display message, if specified, appears in the system tray and settings app under **Privacy & security > App permissions** pages while the capability is in use.
+The display message, if specified, appears in the system tray and settings app under **Privacy & security > App permissions** pages while the capability is in use. Display messages should be provided before the capability is accessed and should continue to be provided until after the apps terminated access to the capability.
 
 ## -see-also