1. Is 'hiding' a notification the only way to remove it from the list or is there a 'delete' option that I am not seeing? 2. Does a notification have to be 'read' before it can be hidden or can it be hidden while unread? 3. When a notification is marked as read then unmarked as unread, does the sender know that the recipient has read the notification? 4. What purpose does marking a notification 'as read' serve? Is it so someone can keep their notifications organized, so the recipient knows the notification was read, both reasons, or another reason? Many thanks.