I'm not surprised that few people in GA know about this. I was introduced to this when I first got into an aircraft with cabin crew. It was a way of quickly briefing them whenever there was a non-standard event or an emergency. Another of these mnemonics is TEST: T ime available; E mergency (type); S ignals; T ransmit additional instructions (structural damage, restricted exits, loss of landing gear, etc). But I think I'll stick to NITS.
PM