We have another quick but important announcement today.

Bing, along with the other search engines that are a part of Sitemaps.org, has announced support for the following Sitemap enhancements:

1. 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.

2. 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.

Let’s take a look at some sample code from a Sitemap.xml file to see how the schema change affects your work. The lastmod attribute in the new Sitemaps protocol requires a date value rather than a string. The following example is valid code because the lastmod data matches the type defined by xsd:date:

<?xml version=”1.0″ encoding=”UTF-8″?>
<urlset xmlns=”http://www.sitemaps.org/schemas/sitemap/0.9″>
   <url>
      <loc>http://www.example.com/</loc>
      <lastmod>2005-01-01</lastmod>
      <changefreq>monthly</changefreq>
      <priority>0.8</priority>
   </url>
</urlset>

The following is an example of a lastmod field entry that never properly worked, but was technically valid because it matched the previous protocol as a xsd:string:

<?xml version=”1.0″ encoding=”UTF-8″?>
<urlset xmlns=”http://www.sitemaps.org/schemas/sitemap/0.9″>
   <url>
      <loc>http://www.example.com/</loc>
      <lastmod>last fall at noon</lastmod>
      <changefreq>monthly</changefreq>
      <priority>0.8</priority>
   </url>
</urlset>

Please see Sitemaps XML format for more information on the current Sitemap protocol. Once you have your Sitemap ready to submit, you can either log on to Bing’s Webmaster Center tools. You’ll need to add in your site’s URL at the end of the submission string before you submit it. Note that Bing only accepts XML files for Sitemaps.

If you have any questions, comments, or suggestions, please feel free to post them in our Sitemap protocol forum. Thank you!

Rick DeJarnette, Fabrice Canel

Edited: May 22, 2023: ping support removed.