For device-menu navigation, treat EPUB 3 nav as the primary navigation document and NCX as a compatibility resource for older reading systems. Keep both distinct from a contents page inside the book. All three may display chapter names, which is why mere file presence can look more convincing than it is.
Map five chapters across four columns
Create a row for each chapter with its source heading, nav label and destination, NCX label and destination, and in-content link. Every value in chapter one's row should resolve to chapter one. Five entries can exist in each resource while the third entry still points to chapter two.
Nav is the EPUB 3 Navigation Document. NCX may be included for legacy compatibility. An in-content table of contents is a page a reader encounters in the book. Use the standard roles in EPUB 3.3 rather than describing these concepts as product inventions.
Choose navigation inclusion in Rune Studio
Select the five chapter sources in the EPUB wizard, arrange them from chapter one through chapter five on Chapter Order, and enable navigation inclusion for the intended headings. Review the positions of title and navigation pages as well. The final Review and Export page should show the planned sequence and included entries before the EPUB is generated.
Rune Studio's current output includes nav.xhtml and a compatibility NCX. In a three-chapter inspection, nav contained three chapter destinations and NCX contained three navigation points, each corresponding to chapters one through three. The six-item spine ran through title, nav, three chapters, and colophon, and the local package check was valid.
Separate static proof from device behavior
That inspection establishes where the packaged links point. It does not show how a particular device labels its menu or where a tap lands in the rendered view. Those behaviors were not observed and should remain an explicit device test rather than being reported as successful.
On a target reader, open its navigation menu and select the first, middle, and final chapters. Record the displayed label, the heading reached, and the return behavior. Repeat the same sample from the visible contents page. Judge the device menu and book page independently.
Repair the symptom's owner
A stale label points back to the source heading and Chapter Order. A wrong destination suggests repeated headings or incorrect chapter sequence. A missing device menu requires investigation of reader support and recognition of nav. Do not randomly add or remove NCX and call the result a diagnosis.
Completion has two levels. First, five nav and NCX entries resolve consistently with the five-chapter reading order. Second, the intended device actually moves through representative chapters from its menu. The available evidence reaches the first structural level only. Rune Studio's current EPUB feature scope supports that generation step; the device supplies the remaining observation.
