Permanently delete one of the current user’s reminders, along with any notification it already produced. Get the reminderId from ListReminders or CreateReminder. This cannot be undone, and it is not the usual way to clear a reminder. When the user has simply dealt with one, use UpdateReminder with completed: true instead: that takes it off their active list but keeps it, still readable with ListReminders completed: true and restorable with completed: false. Delete is for reminders they want gone rather than finished — one set by mistake, or for something that is no longer happening. If it is not clear which they mean, mark it done.