SoType(3) on Linux
The text cdad52a804e2, as Debian 7 (Wheezy) shipped it.
The SoType class is the basis for the run-time type system in Coin. Many of the classes in the Coin library must have their type information registered before any instances are created (including, but not limited to: engines, nodes, fields, actions, nodekits and manipulators). The use of SoType to store this information provides lots of various functionality for working with class hierarchies, comparing class types, instantiating objects from classnames, etc etc.