Incidentally, Clarence, I've had a nose though my sources and have found no reference to the Germans issuing a "do not engage" order with regard to the IS-2 - which is not entirely surprising as (however well armoured it was) it was not immune to the long 75 and 88mm tank guns meaning that any of the Big Cats (and even a late Pz IV if it caught one in an unfavourable position) could engage an IS-2 with a reasonable chance of success.
