Moving onto business, today's IK lesson discusses the pole target - essentially a second anchor that restricts the IK path - so that something like a human leg IK mesh would not bend the opposite, unintended way. Though this increase in realism comes at a price of rigidity; for the tendril armatures can no longer be rotated (but still movable) as a whole.

In conclusion, pole targets can ground the simulated positions of an IK between targets but restricts a portion of armature rigging. If you desire functionality over stability, I discourage you making and linking pole targets to your IK armatures.