Microsoft, along with rivals Google and Yahoo, has announced that the maximum number of references supported for sitemaps has been consistently boosted. The sitemap enhancements affect not only Bing, the evolution of Live Search, killed off at the start of this month, but also competitor search engines that participate in Sitemaps.org. The Redmond company has indicated that webmasters will be able to build extensively larger sitemaps moving forward. Bing, but also Google and Yahoo for example, now come with support for sitemaps including up to 50 times as many references as before.

“You can now include up to 50,000 references (either URLs or links to child Sitemaps) in your sitemap.xml index file. Until recently, Sitemap files only supported about 1,000 child references. This enhancement will be very useful to extremely large sites, as now a single, large Sitemap index file, referencing up to 50,000 child Sitemap files, each of which referencing up to 50,000 URLs, can reference up to a total of 2.5 billion URLs,” explained Rick DeJarnette, Bing Webmaster Center.

Microsoft started rolling out Bing at the end of May 2009. By June 3rd, the search engine that killed Live Search was live worldwide. And just as Bing became accessible globally, the software giant indicated a strong commitment to continuing to innovate its search engine. Sitemaps are a key aspect of the search engine optimization process, and enable webmasters to make their website easier to crawl and index by search engines.

“A slight modification of the Sitemaps XSD schemas helps developers and applications to validate Sitemaps content against defined types. For example, the attribute lastmod is now xsd:date instead of xsd:string. We aim to improve Sitemaps quality with this modification. Note that the Sitemap schema version is still identified as version 0.9,” DeJarnette added.