Mafia 83. Doctor Who: Aliens in London

Please enlighten me, what does NNV mean?

NNV stands for "don't hang anyone." It's also a vote. When there's no certainty, you can vote this way. It's not the best option, but it's hard to draw definitive conclusions in this situation, especially since I don't know anyone here yet. And I don't want to just randomly vote to eliminate someone just because they're being pointed at.