Typographic style is more than cosmetic
There is disagreement about the role and importance of typographic
style (source code formatting and commenting) in program comprehension.
Results from experiments and opinions in programming style books are
mixed. This article presents principles of typographic style consistent
and compatible with the results of program comprehension studies. Four
experiments demonstrate that the typographic style principles embodied
in the book format significantly aid program comprehension and reduce
maintenance effort.
—Authors' Abstract