The following table shows how the command is encoded for network transmission:
This command can be used to hide object nodes. An object that is hidden should not be rendered in the world. Of course, clients that are not attempting to show a realistic/immersive view of the world can still make the node accessible for editing and so on.
One intended use for hidden objects is to allow efficient rapid creation of complex objects. Consider a game scenario, where a player wants to launch a rocket for instance. If the rocket is represented as its own object node (with associated geometry and material(s), of course), creating it at the press of the fire button would be problematic. With a hidden object created in advance, it is enough to simply move the node to the proper location and un-hide it, which requires no network roundtrips.