Many years ago Colorado Plateau canyoneers were trying to establish a standard rating system for technical canyons that would entail all the different conditions one would encounter in the various slot canyons. Rich Carlson, through the ACA, created the ACA Canyon Rating System and it was quickly adopted by beta providers and the canyoneering community.
The official documentation differs slightly from how beta providers have used it. Below is my understanding of the rating system based on these observations.
5 questions out of a pool of 21 questions
I track questions that are answered and answered correctly for a purely non-scientific and easy-to-cheat system. Enjoy!
The Colorado Plateau and the ACA aren't the only organizations that have created canyon rating system. Check out some of the others that exist or have existed.