Often looking through old code you find yourself wishing for more comments, or even more correct comments. Rarely, less comments.

But looking at some code I'm debugging at the moment at work I found the following bizarre idiom (details changed to protect the afflicted) ...

#ifdef DOC
C  Some fortran comments.
C  Yes, ordinary comments, nothing fancy like preprocessor directives, but if you want
C  your code without a paragraph explaining what it does, you can just preprocess it
C  and remove it.
C 
C Perhaps they'd expected that their fellow developers would write essays in the
C source code that would make it hard to follow, but then, you'd still need to edit
C the full source code to debug and develop it, right?
C
#endif