In
health care, code red means
fire. This is used to prevent
panic (imagine what would happen if they announced
Fire on Wing 100 over the speakers).
Indeed, most health care facilities use some modification of code red to hide it even from visitors who know what code red means. This modification is known only to the employees of that facility.
My favorite modification was one I saw in an instructional video when I worked as a certified nursing assistant. In this video they had fire on a wing, but instead of announcing Code Red on Wing 100, they said over the speaker system Doctor Red, please come to Wing 100.