The Purpose of Tech Books

I just got asked one too many times, "What's in this book that's not in the man pages?" And I've snapped.

I'm blogging my answer, so I can point here and save myself from typing the answer again.

I'm best known for writing about BSD technologies, a field where the developers are notoriously detailed in their documentation. If you look at the man pages for any open-source BSD, you'll see that everything is included. If something is missing, it's a bug. In addition there are extensive...