SoSFBool(3) on Linux
The text 6a9bf25a9c16, as Debian 4.0 (Etch) shipped it.
The SoSFBool class is a container for an SbBool value. This field is used where nodes, engines or other field containers needs to store a boolean on/off or TRUE/FALSE value, like for instance as the 'on' field of the SoPointLight, SoSpotLight and SoDirectionalLight node classes.