General guidelines for URLs in Sitemaps

* A Sitemap can contain a list of URLs or a list of Sitemaps.

* If your Sitemap contains a list of other Sitemaps, you should save it as a Sitemap index file and use the XML format provided for that file type. A Sitemap index file cannot list more than 50,000 Sitemaps.

* A Sitemap file can contain no more than 50,000 URLs and be no larger than 10MB when uncompressed. If your Sitemap is larger than this, break it into several smaller Sitemaps. These limits help ensure that your web server is not overloaded by serving large files to Google.

* Specify all URLs using the same syntax. For instance, if you specify your site location as http://www.example.com/, your URL list should not contain URLs that begin with http://example.com/. And if you specify your site location as http://example.com/, your URL list should not contain URLs that begin with http://www.example.com/.

* Do not include session IDs in URLs.

* The Sitemap URL must be encoded for readability by the webserver on which it is located. In addition, it can contain only ASCII characters. It can't contain upper ASCII characters or certain control codes or special characters such as * and {}. If your Sitemap URL contains these characters, you'll receive an error when you try to add it.