As I work my way through the wiki learning the structure, I find that:
1. There is only one portal page per topic?
2. Categories are support for namespaces allocated to the review process?
3. There should be only one top-level Category that correlates to the
portal for that topic and all other categories should be
4. Pages can be directly related any namespace and not necessarily
fall under a sub-category?
The following link is an example tree using Artwork: