C1PrintDocument supports outlines. The document outline is a tree (specified by the Outlines property), with nodes (of the type OutlineNode) pointing to locations in the document. The outline is shown on a tab in the navigation panel of the preview, and allows navigating to locations corresponding to items by clicking on the items. Also, outlines are exported to formats supporting that notion (such as PDF).
To create an outline node, use any of the overloaded Outline constructors. You can specify the text of the outline, the location within the document (a render object or an anchor), and an icon to be shown in the outline tree panel in the preview. Top-level nodes should be added to the Outlines collection of the document. Each outline node may, in its turn, contain a collection of child nodes in the Children collection, and so on.