This is the highest-level category for all articles in encyclopaedia.
Articles do not appear in this category directly, but at lower levels in its hierarchy of subcategories.
There are two systems of subcategories available to enhance browsing.
It should be possible to reach any article or category through either of these systems.
The first system is organized under Category Fundamental categories.
This begins with a small number of thematic classifications, based on fundamental areas of human knowledge.
The second system is organized under Category Main topic classifications.
This begins with a somewhat larger number of thematic classifications, some reflecting more detailed fields of knowledge.
This category has the following 4 subcategories, out of 4 total.