The original intention of creating the categories and requiring departments to divide by category many years ago may have been to improve public knowledge about the understanding of the act. But since the software was designed to allow the refinement of categories, it has become used as a tool for managing requests internally, and in particular as a mechanism for separating requests that are thought to be politically risky. The irony is that this mechanism has been changed in its purpose over time.
A reasonable question might be why any government department needs to categorize requests for its internal purposes. What legitimate purpose pertaining to the operation of the law is served by the categorization of requests by occupation?