Use of variables 
       How to speak about "this chapter" 
 How to make several variants of the text 
 Mako's Python functions 
       Basics of Mako functions 
       How to automatically generate a DocOnce file with repetitive structure 
       How to deal with almost repetitive structure 
       How to treat multiple programming languages in the same text 
 References 
Below we describe the work flow and how we can utilize many nice DocOnce features when writing chapters for a future, potential book project.