reference notes that I made for myself or found in mapbox's support or #mapbox over the years, to learn carto, and more advanced usage of tilemill. Thought of it to be a continuation of http://www.mapbox.com/tilemill/docs/manual/carto/ and http://www.mapbox.com/tilemill/docs/guides/styling-labels/ License CC-SA or something freer if I feel like it .