Is this site available in Kindle format?

Good question. The answer is no, for several reasons. Firstly, this site simply works better on the web; as a textbook it would be just about acceptable, but as a Kindle book less so.

There are lots of downloads, web hyperlinks and bits of code for copying that wouldn’t work on a Kindle. On a more practical level, the Kindle doesn’t display code snippets particularly well.

It’s a question worth thinking about because – as I outlined in this post – some things just don’t work at the moment as eBooks.

<i> or <em>? <b> or <strong>?

Those of you with some knowledge of HTML will have noticed me telling people to use of  <strong> and <em> tags for bold and italic, instead of the familiar <b> and <i>. What’s that all about?

It’s true that <b> and <i> will give you bold and italic in any web browser, but there are valid reasons (albeit complicated ones). The w3c (guardians of all things web) have published this statement. If I’ve understood it correctly, to take the example of italics, it’s trying to distinguish between italics as way of conveying emphasis and the other uses of italics, such as denoting foreign words, book and film titles. This would be important if your audience were using the text-to-speech function, for example. So, if you’re using italics for emphasis, use <em> and if you’re using them for formatting, use <i>.

Bold text is a little different. As an editor, I’ve occasionally used it to highlight the first word(s) of a paragraph, where the word’s acting as a subheading or the name of a speaker in an interview, for example. But never within a paragraph.

It’s a tricky subject – I await your thoughts. But the lesson might be: think about your italics and lay off the bold.

Why are my text sizes and spaces being ignored?

You may have produced perfectly valid HTML and CSS, where you’ve defined margins, indents and text sizes, only to find they’re not reflected in the final output.

The simple answer is that you’ve done nothing wrong: the Kindle has just ignored them. I don’t have documented evidence for all of this, but here’s what I think is happening:

1. The Kindle basically ignores any instructions on text size. This is understandable, because this should be the choice of the reader and not you. If precise layout is crucial to the understanding of your book, then eBook formats are not a good choice
2. The best measure to use for size (for indents and spacing) is em. This means the spacing will be proportional to the font. I believe the Kindle rounds up and rounds down these values to the nearest whole number or 0.5em
3. The maximum allowed left-indent appears to be 2em. Therefore, if you have indented paragraphs and text indents, I recommend you set the first to 1em and the second to 2em
4. Right-indents are ignored.

Why are there different Kindle formats?

The eagle-eyed among you may have noticed that three formats seem to exist for the Kindle – .mobi, .prc and .azw. Mobipocket Creator, for example, creates .prc files, while Calibre produces .mobi files.

There is actually no difference between .mobi and .prc – you can change the extension of one file to the other and it will stay the same. Both will open in Kindle Previewer. Amazon bought the format from Palm and a .prc extension was necessary to open files on Palm devices.

If you buy books from the Kindle store, they have the extension .azw. This format has the same characteristics as the other two – the difference is that it uses a proprietary digital rights management (DRM) system.

Options for the blind and partially sighted

eReaders are a boon to the visually impaired, but remember their needs when you put your book together. Don’t try and fix the text sizes – the reader is king here. If there’s a text-to-speech option, as in the Kindle Store, make sure it’s enabled.

In addition, make sure you add alternate text to any images you include, with a description of what the picture is. At its simplest, the code you use to insert an image will be:

<img src="dog.gif" alt="picture of a golden retriever" />

In a web browser, the contents of the alt=" " tags produce those little text boxes that appear by the mouse pointer when you hover over an image. On an eReader, it should act as a spoken description of the image when you use the text-to-speech function.

Disappointingly, the Kindle ignores these directives, which is frankly unacceptable – hopefully this will get fixed in a subsequent software update, so you should still include them. And ePub files will not validate unless images have alt tags.