| ExtensionMetadata | Container for attributes of a  SiteMapURL defined by a sitemap
 extension. | 
| ImageAttributes | Data model for Google extension to the sitemap protocol regarding images
 indexing, as per http://www.google.com/schemas/sitemap-image/1.1 | 
| LinkAttributes | Data model for Google extension to the sitemap protocol regarding alternate
 links indexing. | 
| MobileAttributes | Google mobile sitemap attributes, see
 http://www.google.de/schemas/sitemap-mobile/1.0/ and
 https://www.google.com/schemas/sitemap-mobile/1.0/sitemap-mobile.xsd:
 Mobile sitemaps just contain an empty "mobile" tag to identify a
 URL as having mobile content. | 
| NewsAttributes |  | 
| VideoAttributes | Data model for Google extension to the sitemap protocol regarding images
 indexing, as per http://www.google.com/schemas/sitemap-video/1.1 | 
| VideoAttributes.VideoPrice |  |