Yahoo! has recently introduced the “No Open Directory” (NOODP) tag to webmasters.
If you’re one of the webmasters who has a link pointing to your website from the Open Directory Project (ODP) since years ago, your ODP title and description may have not expired and do not reflect what your website is about anymore. However, Yahoo! directories doesn’t necessarily update your website’s title and description to reflect the ones from your homepage.
The explanation on the Yahoo Search Blog,
We look at multiple sources for titles and abstracts, including page content, anchor text in the links to a page, Yahoo! Directory and the Open Directory Project (ODP); and we pick the best based on our algorithms. You might have seen some of the features that we have implemented with this approach, such as quick links for Wikipedia, and local business data. However, some webmasters have had issues with titles and abstracts in ODP and have adopted the ‘NOODP’ META tag to indicate to search engines not to use them.
From now on if you include one of the tags in your HTML documents, Yahoo! Slurp will recognize the NOODP tags below. Yahoo! will not consider showing your old ODP titles or descriptions in its search results.
META NAME="ROBOTS" CONTENT="NOODP"
or
META NAME="Slurp" CONTENT="NOODP"
Both Google and MSN have always been supporting their own NOODP tags.