In passing, I noticed I had a broken link to a Google CSE documentation page:
http://code.google.com/apis/customsearch/docs/special_results.html
Searching a little, I found the page had moved to
http://code.google.com/apis/customsearch/docs/promotions.html
A cached version of the originally linked page is still available, so I did a side-by-side comparison:
Hmmm…