Those of use who have been around in the hobby for quite a while will no doubt remember the 'Loco-Hauled Travel' and 'Diagram Diary' books published by Platform 5 and Metro Enterprises in the 1980s and 1990s. For those who aren't familiar with the books, they detailed loco diagrams for all classes, and later editions also included headcode listings. (HSTs were excluded for the first 10 years or so - for a start, they were officially classified as units until around 1987, secondly very few people were interested in them and most tended to avoid them, and thirdly, the all-line timetable recorded which trains were HSTs in it.) The recent threads on diagrams made me wonder how many people would actually consider buying such a publication nowadays if it existed, perhaps even one including units given that there seems to be a growing interest in people actively going to travel on them. Or do people nowadays have an expectation that all 'gen' should be provided for free? Before anyone asks, I am not considering producing such a book! I'm just interested in people's thoughts.