It's a trademark for this train. The rakes do not change CC, but they do have a very weird coaching order. I traveled by this train a couple of times between NJP and BNC, and on both occasions, there were no boards on the coaches ( only paper indications or chalk indications) and the coach order was very counter-intuitive. With a few 2A coaches sandwiched out of order between 3A coaches and some 2A coaches at the ends of the rake.
It is probably NFR's way of saying that only the ones able to identify their coach are worthy of traveling on this. :P :P