I would disagree with this. In my opinion, namespaces are totally unsuitable to express hierarchical structures. My view is here: The Most Legit Use of Namespaces - #10 by gax
I think namespaces are suitable and needed for two areas:
- To disambiguate names if one absolutely can’t find unique names.
- Nicole Smith and Nicole Blanc: Both “Nicole Smith” and “Nicole Blanc” will be perfectly fine, unique names. Namespaces are not needed.
- A good use is for dates, there are many Januaries, they can be kept apart.
- Project/subproject is also a good use case.
- To resolve conflicting requirements. An employer and a customer might require the same tag for different purposes. Corp/tag and Customer/tag can keep them apart.
- To group pages (e.g. tags) together without establishing a hierarchy.
- A taxonomy (e.g. animals) could live in its own namespace. This prevents contamination of a private namespace.
- A company might prescribe their own classification scheme, this should also sit in its own namespace to distinguish private from official tags.
Hierarchies can then be expressed on top of these unique names by properties or indentation.