Retargeting
Assign to joints, record to controls.
Retarget
Any moderately complex character will have parts better suited for capturing and others for recording onto.
For example, in order to control a simulation with IK controls, we must first assign Markers onto the underlying joints driven by those IK controls. Then, we retarget those joints back onto the IK controls.
In this example, markers are assigned to the upper body controls, but then to the joints of the lower body. We don't want keyframes on these joints, so we retarget these keyframes onto the IK controls.
Reassign
The opposite of Retarget.
Rather than assigning to joints and retargeting to IK controls, we assign to IK controls and reassign to joints. Same coin, different side; which one do you prefer?
Reparent
Use Reparent
when you selected things in the wrong order and want a do-over.
Success!
Untarget
For when you don't want anything recorded for this Marker. Useful for utility Markers, like twist joints or extra spine controls or just Markers without a corresponding control.