The Sitemaps protocol has been upgraded to allow Webmasters to use one Sitemap (a file that contains URL info and meta-data for all the pages on a Web site) to support multiple sites on different hosts--and submit all the data on a single platform. Before, Sitemaps had been required to be on the same host and path as the URLs they contained--now, they can exist where the site owner chooses to host them, making them much easier to manage. Webmasters will need to add a line to their robots.txt file to direct crawlers to the differently-hosted sitemap--but that's about it.
While each of the Big Four engines will be supporting this change, Yahoo is pegging it as the result of listening to Webmaster feedback. "We know that segregating user facing content from feeds, like Sitemaps, is important," wrote Priyank Garg, director of product management at Yahoo Search. "We've also learned that managing feeds for large websites or websites using third party feed publishing services is critical. We hope this enhancement helps address those needs."