Am wondering if anybody has a complete example (explained below) of a 
book cover: front, spine and back. It doesn't matter how simple or 
complicated the example. Am one of those people who, once he sees an 
example, can generally work out the necessary adaptations.

By a complete example I mean the kind of thing found here Creating a 
style file in ConTeXt | Random Determinism 
<https://randomdeterminism.wordpress.com/2009/10/21/creating-a-style-file-in-context/> 
where the writer explains things bit by bit but importantly, offers a 
summary of the code at the end. I probably don't need the lengthy 
explanation but the summary of code is most helpful - except that it is 
not about a book cover:-)

As a relative newcomer to ConTeXt, I have found complete examples of 
something I want/need to do very useful. Of course, many such are on the 
wiki, but from time to time I need something else, and right at the 
moment I need a bit of guidance for a book cover, and an example might help.

Julian