A sitemap can carry more about a page in elements from other namespaces, declared on the urlset root.
Everything here is from Google’s documentation pages (read through summaries, so the words are ours); the viewer checks
each element against what they say.
Images
Namespace http://www.google.com/schemas/sitemap-image/1.1, usually the prefix image. A
url holds up to 1,000 image:image elements. Each has an image:loc, the address of
the image, which is required. The elements image:caption, image:geo_location,
image:title and image:license were removed from Google’s documentation, and the viewer says so
when it meets one.
Video
Namespace http://www.google.com/schemas/sitemap-video/1.1, prefix video. A
video:video element in a url holds:
| Element | Status and limits |
|---|---|
video:thumbnail_loc, video:title, video:description | required; the description is at most 2,048 characters |
video:content_loc, video:player_loc | one of the two is required; each differs from the page’s loc |
video:duration | whole seconds, 1 to 28,800 (8 hours) |
video:rating | 0.0 to 5.0 |
video:publication_date, video:expiration_date | W3C Datetime |
video:family_friendly, video:requires_subscription, video:live | yes or no |
video:restriction, video:platform | a space-separated list (country codes; web, mobile, tv) with a relationship attribute of allow or deny |
video:uploader | at most 255 characters |
video:tag | at most 32 for a video |
video:view_count | the number of views |
video:price | not supported in video sitemaps; removed from Google’s page |
News
Namespace http://www.google.com/schemas/sitemap-news/0.9, prefix news. A url has
one news:news, holding a news:publication (with news:name and
news:language, a two or three letter ISO 639 code), a news:publication_date (W3C Datetime) and a
news:title. A news sitemap holds up to 1,000 of them, and only articles from the last two days.
Alternate-language versions
The namespace is XHTML’s, http://www.w3.org/1999/xhtml, prefix xhtml. Each url lists
every version of the page, including itself, as an xhtml:link with rel="alternate", an
hreflang (a language, with a region if needed: de-CH) and an href with the full
address.
<url>
<loc>https://www.example.com/english/page.html</loc>
<xhtml:link rel="alternate" hreflang="en" href="https://www.example.com/english/page.html"/>
<xhtml:link rel="alternate" hreflang="de" href="https://www.example.de/deutsch/page.html"/>
</url>Other namespaces
The mobile extension (http://www.google.com/schemas/sitemap-mobile/1.0) is recognised by that name, from
memory: no page about it was read. An element from any other namespace is counted in the summary and shown in the tree,
and not checked.