I'm not a fan of classification. It's very difficult to come up with a classification scheme that's useful when what you're most interested in is things that don't fit in, things that you didn't expect. But some people decided that every page should carry classification. They came up with a scheme, based on page names, to establish a classification structure for a wiki. And these people who care about classification maintain it.
A Conversation with Ward Cunningham (2003) - Exploring with Wiki