Hello! I hope this isn't too late for you. I remembered coming across this at one point, and it took me a few minutes to find the name of it. Unlike what was written above, however, it is exceedingly complicated, but just as accurate. Dances written by this method can be recreated long after any visual of it is gone and the choreographer is dead to near-perfect accuracy.
It is call Labanotation. Use that word in your search terms, and you should get what you are looking for. It's not something that is easy to learn, from what I understand, since it makes a different mark for every move the body can do. It is very much a matter of learning a new language, the written language of movement.