The TOC is described in the Design's '<toc>' node subnodes. The node represents either a folder or a terminal item. The rules:

1. The node’s name must match the name of the corresponding topic file.
2. The node must contain a topic title.
3. Terminal item nodes contain only a title.
4. Folder item nodes contain both a title (first) and sub-nodes.
5. A node’s name or title must match the value of the title of the according topic file.
6. Sub-nodes may be folders or terminal items.
7. Maximum nesting level for nodes is 3.

For example, the Manual’s System Guide section describes subsections that have a nesting level of up to 2 as follows:

The icons

The title of each TOC section is prefixed by an icon. The folder item's icon indicates its opened/closed status. The terminal item's icon can be a standard or a question mark icon. This can be determined in the icon's properties ('S' or '?', see ). You can replace default icons in particular sections using the 'icon' attribute; for example the last section of the Manual:

<obtain icon="?">How to obtain</obtain>