I don't know how many times I have chatted in-game only to have no response. I figure if anyone is reading the chat, that person is a rare player. I've used Nh a number of times with no meaning other than my surprise at their hand being better than mine. Usually this might happen during a coin flip. I have QQ, the villain has AT, the community cards show an A, he wins. "Nh" I say, after all it is luck on coin flips. I am not upset, I don't think he played badly or me either. I know it will win approx 50% of the time and lose the same. I might say "nice play" if someone prices me out of the pot just enough that it is not profitable for me to continue and when I don't have an all-in hand. I have to fold. No hard feelings, the villain is assuming the risk. Another time, when I have the nuts, I will call and set the villain, so it's all the same. "nice play" this time "gotcha" the next time.