By default, each new node starts with the same set of properties. You can change the default properties by defining a node called DEFAULT.
You can also use the TEMPLATE keyword to make a node inherit it's settings from any other node. The node you use must be defined earlier in the config file than where you use it.
You can make template-only nodes that are not visible in the map, by not including a NODES line in the node. Template nodes can also use templates, to build up a hierarchy of 'types'.
NOTE: The TEMPLATE line should be the first line in the NODE definition, as it will copy the configuration over the top of anything else you have already defined for that NODE.