This document discusses 13 different ways of understanding and analyzing the content of artwork, including representation, verbal supplements, genre, materials, scale, temporality, context, relationship to art history, persistence over time, iconographic tradition, formal properties, attitudinal gestures, and biological/physiological responses. It emphasizes that analyzing content is complex and demands attention to different levels and factors, and that no work can have a true zero level of content. Fully understanding and relating to an artwork requires balancing and relating these many codes and factors produced by the brain in response.