This document discusses the importance of communicating design decisions to stakeholders. It notes that design can be subjective and intuitive, making it difficult to explain decisions to others. The key message is that communicating the rationale for design work will become more important than the design itself. It provides principles for design communication, including identifying problems, describing solutions, empathizing with users, appealing to business needs, and securing agreement. Overall it argues that explaining design choices is critical and one of the biggest failures is the illusion that communication has already occurred.