A glitch that hides the (MC) tag? Did I read that correctly? That sounds really odd, because I'm somewhat certain, maybe 60%, that the (MC) tag will still show if two people are using the same network at all. I think that was the basis for a suggestion that would let, say, siblings play together in public servers together without being banned/punished for MCing, which is the only reason I know about it at all. I could very well be wrong.