A place to provide an extract for people to sample the book.
How it works
Create a smaller version of the Book.txt file with the bit you want to show off. This can include any content, and is tagged using the same tags.
Save it as Extract.txt and include it with the rest of the files.
Note: the extract is optional. It provides control to the author or publisher over what is allowed to be used as an extract. Some online retailers simply grab the first tenth of the book and display that. This, however, may not show the book to its best effect. The extract can contain anything, and is a handy way of displaying an exerpt that best sells the book and exemplifies its overall content.