So that the SE does not take the description from those directories when displaying the page on the SERP. Its for site that has listing on DMOZ and Yahoo directory
This Tag is used to avoid search engines from displaying outdated descriptions if you created an account in DMOZ(Noodp) and yahoodirectory(noydir) Here is how to do it, <meta name = "robots" content=â€NOODP,NOYDIR†/> If u have problems only with Yahoo, <meta name = "slurp" content=â€NOYDIR†/> If u have problems only with Google, <meta name = "googlebot" content=â€NOODP†/> Regards, Hashif
noodp: This directive is only supported by Google, Yahoo and Bing and prevents the alternative description from the ODP/DMOZ from being displayed in the search results. noydir: This directive is only supported by Yahoo and prevents the alternative description from the Yahoo Directory from being displayed in the search results.
When one of your web site’s pages shows up in a list of results on a search engine, what do people see? Often the contents of the description tag of your pages are displayed in the search results. At other times the search engines will display portions of your page’s content which contain words used in the search query. This helps people to see if your page is relevant to their search request. Sometimes, if you are listed in DMOZ (ODP), the search engines will display snippets of text about your site taken from them instead of your description meta tag. You can force the search engine to ignore the ODP information by including a robots meta tag like this: <meta name="robots" content="noodp" />. The "NOODP" robots meta tag is fully supported by Google, Yahoo!, and MSN.