Yes, it looks like (besides the leftover "ITA" comment in the guide!) that this is simply the ITA guidelines. From Carl's remarks, you can tell that ITA is not

Yes, it looks like (besides the leftover "ITA" comment in the guide!) that this is simply the ITA guidelines. From Carl's remarks, you can tell that ITA is not a 'normal' Lisp program. Most Lisp programs do not preallocate ~5K of data structures and fail-fast if they exceed that, for example. Compare to the more conventional Norvig style guide (who is also of course at Google today, coincidentally): http://www.cs.umd.edu/~nau/cmsc421/norvig-lisp-style.pdf http://www.cs.umd.edu/~nau/cmsc421/norvig-lisp-style.pdf (PDF)