Thanks for contributing to the Cookbook. Please follow these guidelines. Some are only a convention, some are important for epub generation.

Titles

(important) the first section in a chapter should be a subsection: ## title (indeed, the section name in the epub is the chapter name).
titles are like a sentence, only the first word is capitalized.
if you refer to functions, use markdown syntax too (backtics).

Lists

numbered bullet lists (1.) should be used only at the first level. For the next nested levels, use normal non-numbered lists.

functions should generally be referenced with backtics. There is no need to capitalize them in the age of markdown: write function instead of FUNCTION.
indent code using the predominant style. If unsure, check what Emacs lisp-mode does.

use ~~~lisp for code snippets.
snippets must start at the beginning of a line. Don't indent the ~~~lisp code fence.
code snippets must be preceded and followed by a newline:


Here's a snippet:

~~~lisp
(defun oh ())
~~~

This snippet...

don't write the lisp prompt like "CL-USER> " unless it is very important for the example. This is mainly due to ease copy-pasting.
to show a snippet's result, use ;; => result on the same line if the snippet was on one line, otherwise you can do:

(print :abc)
;; :abc

If the result is large, use another code block, without comments.

lines should not exceed 64 characters, otherwise the PDF will truncate them and show a horizontal scrollbar.

We should not abuse from embedded content, such as youtube videos.

Please exclude them from the EPUB generation with these flags:

<!-- epub-exclude-start -->
<!-- epub-exclude-end -->

We must tweak the markdown links so that internal links work in the EPUB reader. See fix-epub-links.sed to add your link or just ping us on GitHub.