Help! My NCX file is missing.- Diana Kimpton

Self publishing for the Kindle is easy – you just follow the instructions in Amazon's Kindle Direct Publishing guide and let the Mobi Pocket Creator do the work for you. Trouble is, if you download the Amazon Kindle previewer and test your ebook on it you'll find that clicking one of the buttons gives the worrying result:

Missing NCX file

Judging by many of the ebooks I read, not all publishers and indie authors realise what this is or that their book would be better if it had one.

NCX stands for Navigational Control for XML application and the NCX file creates the little marks called 'nav points' that you sometimes see on the progress bar at the bottom of the screen. If they are there, you can skip backwards and forwards along the bar between nav points using the 5 way controller. Without them, readers can only navigate through the book using the page forward and back keys, the search facility or, if the publisher has provided one, with the interactive table of contents.

In most books each nav point is the start of a new chapter, but you can make the marks appear anywhere you like. For example, at subdivisions within a chapter or at diagrams that you know the user might often want to skip back to. The nav points will often exactly duplicate your table of contents but they're much easier to use and anything you do to make reading your book easier must be a good thing.

Luckily, real Kindles don't have the NCX button so ordinary users will never see the error message. So can you ignore the problem? Well, lots of Kindle e books don't have an NCX file so, if you do, you'd be in good company. With a novel, readers may not even realise what they’re missing. But a non-fiction book or an anthology definitely gains from having nav points.

The bad news is that, to include an NCX file, you need to abandon Amazon's Mobi Pocket Creator and start using their command line utility,' kindlegen.exe' instead. Kindlegen just takes all the components (including the NCX file) that constitute an ebook and binds them together. Unfortunately, this means that you have to know what these components are and how to create them individually.

You can probably guess that you'll need at least the text of the book in HTML format, any pictures that are included, the stuff about the author/publisher, a table of contents and of course the NCX file.

You list all these files and other information in a master file called an OPF (Open Packaging Format) and then tell Kindlegen to get to work. That’s not as scary as it sounds – the command can be as simple as 'kindlegen mybook.opf'.

Before you get that far, you'll need to find out exactly what to do by looking on the internet. computerhope.com tells you how to start up a command line session, and easy-as-pie.com is an excellent resource to lead you through the construction of the necessary files. The Kindle publishing download includes a Sample folder (actually the files that make up the Kindle User Guide) that you can use as a model for your own files.

It's all a bit horrible to start with, but constant Googling will eventually pay off and you’ll be able to look at your new NCX enabled ebook with pride.

My latest ebook, Perfectly Pony, is in the Amazon Kindle store,
complete with an NCX file.