I think he was referring to the Choose URIs wisely article. While not specifically directed at filenames, the filename is technically part of the URI.
I still don't think it's relevent to the OP's query. It was about file names, not paths.
Can I offer anything other than criticism? Nope. Can't find anything at the site about file naming conventions. So I guess the short answer is "No".
Sorry to bump an old thread but having worked on some nightmare projects it's good to have some sort of convention to your filenames. I tend to stick to camel case lettering, with images in the format <type><subject><colour> or something like that, eg: