Skeleton > Full Body IK > Add Full Body IK >
These options let you specify the kind of character you want to create the full body IK effectors for and the FBIK joint labelling and naming method you used for your characters.
Identify Joints
Select one of the following options.
When on, labels are used to create the set of full body IK effectors. See Joint labelling.
When on, joint names are used to create the set of full body IK effectors. See Renaming your character’s joints.