This document outlines 13 steps for reducing waste and being more environmentally friendly. It includes instructions to properly separate organic and inorganic waste, reuse materials and leftovers, donate used items to organizations or others, and choose more sustainable options like low-energy light bulbs, reusable containers, and bringing a shopping basket to the store. The overall message is that following this "decalogue" teaches children how to be green at school and help the environment by reducing, reusing, and recycling.