Yahoo's rumored NOYDIR meta tag is now working. It is a tag that allows you to remove the Yahoo Directory's title and description from your Yahoo search results. I applied the tag a few weeks ago to the head of a client's website and the site is no longer showing the Yahoo directory description in SERPS results. The site was listed in the Yahoo Directory a number of years ago, well before the company had any knowleadge of Search Engine Optimization, and so a title was used that wasn't well thought out.
The site eventually got the number two ranking for a popular keyword in Yahoo that gets thousands of searches per day but the site's listing gets less than 500 hundred unique visitors a month. Why? Because the title and description were turning people off and were completely unrelated to the site's focus. I asked Yahoo on numerous occasions to change the title and description but all my requests fell on dead ears.
I implemented the following meta tag about a month ago between the opening and closing header tags
A few days ago I noticed a monumental increase in the amount of clicks coming from Yahoo. It was the usual keywords, no gain in any new keywords, just more traffic. I realized that the search results were now displaying the site's proper title and description, not the outdated one from Yahoo's Directory.
update: Just for clarification. This only applies to sites in Yahoo's search engine results that are also listed in the Yahoo Directory.