EWTE/nav/plusminus

The advantages of this approach are:

• Flexible creation of navigation, as simple as adding a generic template (Template:BasePageGroupNav) to each in a set of pages (and sub-pages) to create navigation.
• Allows for 'previous' and 'next' links.
• The page itself 'knows' that it's part of the book, and can 'behave' accordingly.

The disadvantages of this approach are:

• It does require a number of extensions to be installed (semantic mediawiki, as well as functions for arrays).
• It does not integrate with the book extension, when in principle the functionality is similar.