I am trying to follow this tutorial http://docs.unity3d.com/Documentation/Manual/BlenderAndRigify.html but I am stuck with something. It says in the “Skinning the Rig to the Model” section to
Skin your Shoulders to “DEF-shoulder.R” + “DEF-shoulder.L” and ensure their parent is “ORG-ribs”
But there is no ORG-ribs bone in the rig.