Very few devices support the don't announce feature available in Basecamp at this time. Basecamp is ahead of most device implementations in that respect. To my knowledge only the Zumo 340/350 support it. Older Zumos can be made to not announce by placing via points on intersections or on roadpoints with no address. But that is not related to the basecamp feature. My Montana will always announce no matter what. Hopefully we will see more devices support the feature over time.