I always wondered what these signs meant.

NFPA Diamond

I decided to look into it and it turns out that it is a sign from National Fire Protection Association.

For anyone in the future who looks at it and has the same question, I’ve created an HP-Reveal Aura that’ll explain the sign if you point your camera at it. Pointing at it will reveal the following breakdown of the sign.

NFPA Diamond with AR Overlay

Here it is in action.