if you are using the Eco-Score grade that we compute for products, please note that we will soon be deploying updates to the #ecoscore algorithm. The most visible is that there are 2 new letters: A+ and F so that we can better differentiate products (in particular products from the same category). The corresponding pull request is here: feat: Eco-Score improvements and change of scale: A+ to F by stephanegigandet · Pull Request #10829 · openfoodfacts/openfoodfacts-server · GitHub
And the official doc for the Eco-Score formula is at https://docs.score-environnemental.com/ (in French).
You can see some sample A+ products and F products on the test server:
https://world.openfoodfacts.net/eco-score/a-plus
https://world.openfoodfacts.net/eco-score/f