Because the index contains billions of yahoo web page, yahoo can not manually make changes to the index and depends on the system to a crawl automatically update the search index.
If you want to change the status and the page is crawled and the index, you must make changes to site content or control documents that communicate with te traveler should be on how to handle these pages.
Search engine spiders are becoming more intelligent. It was possible to foll search engines with a simply meta keywords tag some years ago, but search engines have now a deeper understanding of the contents of a web page.
Yahoo recently published a patent applications that gives some insight on how yahoo finds and evoluates keyword phrases on web pages.
What is yahoo's patent all about?
The patent application explains how yahoo parses web pages to find related keyword phrases. Yahoo breaks down the content of web pages into several possible phrases and matches them with a content dictionary.
Yahoo also seems to consider searches and query refinements to determine the topic of a search query. For example, yahoo might monitor a users queries and find out that the terms "woods", "club" and "green" appear during a given query session.
The patent application also contains a lot of information about how Yahoo might work with the gathered information.
What is the essential point of the patent application?
The patent application indicates that yahoo tries to understand conceps instead of single wordr. For example, someone looking for "tiger woods" isn't jus searching for web pager that contain this word combination.
If a page contains the phrase "tiger woods" as well as some related keywords such as "golf", "green" and "clubs" then it is more likely a match for a search for "tiger woods" than a web page that has a story about a tiger in the woods that threatened a boy with the name mowgli that doesn't contain the related keywords.
What does this mean for your website rankings?
When writing web pages, it can be helpful to use related keywords on a web page that has been optimized for a certaim keyword. That will make it easier for search engines to understand the content of the keywords that you use on your web pages.
According to the patent application, it seems to help to use these related keywords close together on a page to make it easier for search engines to find the relation.