Not only is this the most complete reference for terminology, it is one of the most inventive and best examples of infomation design (similar to the work of Richard Saul Wurmann in its approach to looking up information, but without the maps and graphics). It's cross-referenced to the hilt, and contains explanations even seasoned old-timers will find useful. I'm currently using it as a required text in one of my design courses (graduate-level); my only hope is that it stays current and updated as the field and technology progresses.