Understanding Your NCX or Ebook Table of Contents

As I perused the Lulu mailbag this morning I was struck by the number of queries regarding NCX errors in ebook submissions. Some excerpts:

My ebook was recently rejected from retail distribution due to an NCX error. What does that mean? What do I do?

I Googled NCX and was directed to articles on sodium-calcium exchangers? Do I have to know chemistry to make an ebook?

Great questions that unfortunately come as no surprise. NCX errors are among the top three reasons independent ebook authors are rejected from retail distribution. Setting up a fully functional NCX requires some working knowledge of heading styles in MS Word—a feature that a lot of otherwise savvy writers ignore. But never fear, it’s not difficult. And once you’ve applied the proper styles to your document, Lulu’s EPUB Converter will convert them into a fully functional NCX for you.

It’s exactly this simple:

1. Apply Heading 1 style to the Title and to each line containing a Section name (copyright, prologue, etc.) or section (Part 1, Section II, etc.). Heading 1 style will always appear at the top of the next page.
2. Apply Heading 2 style to each line containing a Chapter name or number
3. Apply Heading 3 style to each line containing a subchapter or subsection.

One more thing. I foresee tomorrow’s mailbag asking:

Do I really need an NCX?

So. In a nutshell:

NCX is short for Navigation Control file for XML. (XML is a set of rules for formatting that both humans and computers can read.) It’s that first word in NCX—Navigation—that reveals its purpose. Like a table of contents in a printed book, an NCX helps your readers navigate your work.

But unlike a traditional table of contents, an NCX can’t simply list page numbers. The text in your ebook is scalable (meaning, the size can be changed), and just tilting an iPad 90 degrees can completely change the layout of ebook pages and how many words fit on them. So the number of pages in your ebook is variable from one reader—and even one moment—to the next. A table of contents built on static page numbers is useless, even a little misleading. Navigation has to be connected to something other than page numbers.

Enter the NCX. It contains links to your chapters, sections, and subsections. It lets readers jump from place to place in your ebook without thumbing or scrolling endlessly. You want your readers to have a good experience. So do we, and so do our retail distribution partners. It’s why we collectively urge you to have a fully functional, fully-enjoyable ebook.

Henry K

Distribution Henry is a member of the Lulu eBook Quality Review team.