A read-write enumeration selecting the type of this port forwarding rule: portRange(1) forwards a range of public ports unchanged to the private IP, portRemap(2) forwards public ports to a different private port number, or dmz(3) forwards all traffic on the interface to one private IP. This determines the forwarding behavior and scope of the rule; DMZ is the least secure option since it exposes all ports and can only be the sole rule on that interface, while range and remap rules let an admin open only specific ports, which is more secure. An admin exposing a single internal server to receive all inbound traffic might use dmz(3), while an admin opening only a web server's port 80 would use portRange(1) or portRemap(2) instead, for tighter security.