"Source Code and Internals" is a way of saying "we've printed out all the source code so it can sit on
your shelf". Actually, the original intent of this book was to defeat export laws by putting PGP
v2.6.2 in printed form, and then including instructions on how to scan it into a computer. Of
course, it only takes one person to do this, which is why this 907 paged book probably went out
of print so quickly. However, it is fun seeing an index in the back for variable and function names.