SoNormal(3) on Linux
The text b5b0b4c066e6, as Debian 6.0 (Squeeze) shipped it.
The SoNormal class is a node for providing normals to the state. Coin will automatically calculate normals for you if no SoNormal nodes are present in the scene graph, but explicitly setting normals is useful for at least two purposes: 1) a potential increase in performance, 2) you can calculate and use 'incorrect' normals to do various special effects.