This read-write value forces a slot's backplane port to join a specific ring, Ring A or Ring B, overriding automatic ring assignment, or leaves it unforced. An admin uses this to manually pin a card's port to one ring when automatic insertion isn't picking the desired ring, and like the disable setting it is retained across power cycles. For instance, setting this to forceRingA-1 forces a slot's first backplane port onto Ring A regardless of the module's default ring preference.