SoPickStyle(3) on Linux
The text acf99086cd97, as Debian 8 (Jessie) shipped it.
The SoPickStyle class is a node for setting up how to do picking. By default, all geometry in a scene is available for picking. Upon writing applications with interaction possibilities, this is often not what you want. To exclude parts of the scene graph from pick actions, use the SoPickStyle::UNPICKABLE.