Thanks for this, George. I've managed to miss the ring circuit debate until now.Consider the attached picture.
Assuming the circuit breaker handles are tied together, could you legally use a pair of 12-2 NM cables to go to different points in a kitchen, and then combine them back together to come into, say, an island with a single 12-3 NM cable?
While the neutral current between the breakers and #3 junction box are parallel, the conductor between j-box #1 and its breaker is not a paralleled conductor with the neutral conductor between j-box #2 and its breaker. IMO this doesnot fall within the purview of 2011 NEC 310.10(H)