SoVertexShape(3) on Linux
The text 7c0441aa268a, as Debian 8 (Jessie) shipped it.
The SoVertexShape class is the superclass for all vertex based shapes. Basically, every polygon-, line- or point-based shape will inherit this class. It contains methods for organizing the normal cache, and also holds the SoVertexShape::vertexProperty field which can be used to set vertex data inside the node.