Just getting started? Be sure to check out our Introduction to analytics help page for an overview of common features you'll find on all analytics views.
The target hostnames view allows you to see the hostnames where our URL redirect service is redirecting your audience to.
An (unknown) target result means that our URL redirect service did not find a target location to redirect the request to. In this case it is most likely a 404, which means that the configured 404 response for the host would be returned.
If you have any questions please don't hesitate to reach out. We're happy to guide you further.