Imagine walking into a library to catalogue every book, but the only labels you have are “fiction” and “non‑fiction.” You would miss cookbooks, repair manuals, diaries, maps, and sheet music — and you would never find what you need when you need it. Knowledge auditing faces the same problem: without a practical, fine‑grained set of categories, you overlook huge chunks of what your organization really knows. This chapter builds a set of categories you can actually use to inventory knowledge in a team, a department, or an entire company.