I have downloaded a very nice, fully rigged, character model and have embarked on studying this file and doing some tests. However, from the theoretical POV, I can't seem to grasp the difference between DEF bones and ORG bones in that file. The file is "Mr Incredible" from Blendswap, all credits go to "Crias" the author of that file, not sure if I am allowed to re-upload his file here.
But in theory, how does each bone function and contribute to the rig? considering that a MCH bone is for mechanism, DEF for deformation, CTRL for Control..etc, I'm aware of the terms and functions for each type, except ORG, don't know if it's a sub-type of DEF or I got it completely wrong.
EDIT: Sure, here's a screenshot of the selected ORG bone:
It lies within another bone named "Shoulder.L" and this bone does deform the body upon rotation: