<http://schema.org/description>
"A Google Webmaster Help thread has one SEO nervous that she has multiple sitemaps file but the files have duplication amongst the URLs listed in them.So she has one sitemap file that may have the same"^^<http://www.w3.org/2001/XMLSchema#string>
<https://www.seroundtable.com/google-sitemaps-duplicate-16128.html>