The Search Engine Blog

If you have content on your page that doesn’t need to be indexed by search engines, you can now exclude it from Yahoo!s indexing. This tag tells a spider not to consider text between the tags as part of a search. This could be good for legal disclaimer text, ads or instructional text. This is receiving mixed reviews from SEO professionals and only time will tell if it’s a good tag to implement. The biggest concern seems to be forgetting to close the tag basically telling Yahoo! that nothing on the page should be indexed.

Yahoo! Search Blog: Introducing Robots-Nocontent for Page Sections