"The firewall rules for Template 1 are shown in the screenshot
below. As you click on each cell in the grid in the top of the
window, the bottom pane changes to allow you to edit the data in
that cell. Instead of simply entering a TCP connection type and a
port number, the template firewall offers the SSH service as an
option in the tree view on the left side, which is what this rule
is using to define where the connection is destined. The service
that the template refers to is part of the system definitions and
is read-only, allowing you to see the details in the pane but not
edit them."