This form is used to map hostnames to URLs

1) If your ISP blocks port 80, and you want to be able to update your IP dynamically, you can redirect to a different port by specifying a URL such as http://host1.afraid.org:8080, and setup an additional record, host1.afraid.org as used in this example, as an A record to point to your real IP.

Cloak - Cloak loads page in a hidden frame, so the URL doesn't change to the destination address when redirected, effectively hiding the real URL of your site.

Force Dir Root - force directory root, whether or not to include the URI in the http request when forwarding the connecting http client to the destination site.

For example, with a Web Forward setup like this:
http://site1.afraid.org maps to:

With directory root,
http://site1.afraid.org/anything/anything.html would map to:

Without directory root:
http://site1.afraid.org/anything/anything.html would map to: