Hi Barry,
The purpose of that 3-digit min unique identifier is to make sure the filename is unique. We recommend our clients add it to the tail end of the URL as part of the filename, so headline-of-article-12345.html
It's a requirement before you apply. If you're already accepted as a publisher, make sure your News XML is working properly. You should also start incorporating the new meta keywords tag for GN publishers. We covered that update recently: http://www.brafton.com/news/google-rolls-out-news_keywords-metatag-to-identify-news-content
Jim