To create the network of classification systems, each TOC main topic was placed under all of its own topical parent categories. This process was repeated until a fundamental category was reached. When more than one parent was present, those one or two most related to other TOC topics were selected for the next higher level. The result is a hierarchical article topics classification system that includes references to the network of parents for a topic while also describing a clearer tree structure from each TOC topic to the fundamental categories. Because the Featured articles TOC amounts to an alphabetical index, those topics unique to it are included only under a previously existing Basic outline category, without adding any intervening categories.
A basic outline that includes only the main tree elements was constructed from the more detailed outlines. It includes several TOC topics and a few placeholders. That outline then was cross-referenced with the set of Portal TOC headers and Browsebar labels. The topics from the basic outline then were rearranged to create the portals outline. A few of the characteristics of the basic and portals outlines are listed below.
Excluding items only in the TOC of Featured articles, 36 unique main topics were found. They are included in a separate list.
All main topics under Information and Structure also are listed under one of the other fundamental categories, making these two categories unnecessary for completing the basic network of classification systems.
The twelve Portal TOC headers (with Browsebar labels) were used to organize each of the 36 unique main topics and related placeholders under exactly one heading. This means the existing set of Portal TOC sections is sufficient to uniquely organize each topic under allMain topic TOC systems. This was accomplished by placing a topic under the lowest available heading in a topical classification tree.
The terms used in Portal TOC headers and Browsebar labels do not always reflect the highest topics included in their respective classifications. Adjustments to some of these terms merit further discussion.
The following notations are used to help describe how the outlines were formed.
Bold categories are included in at least one Main topic TOC system.
Italic categories are used as the parent/child in the tree when more than one is present on a line.