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The SITEMAPS protocol allows a webmaster to inform search engines about URLs on a website that are available for crawling. A Sitemap is an XML
XML
file that lists the URLs for a site. It allows webmasters to include additional information about each URL: when it was last updated, how often it changes, and how important it is in relation to other URLs in the site. This allows search engines to crawl the site more intelligently. Sitemaps are a URL inclusion protocol and complements robots.txt , a URL exclusion protocol.

Sitemaps are particularly beneficial on websites where:

* some areas of the website are not available through the browsable interface * webmasters use rich Ajax , Silverlight , or Flash content that is not normally processed by search engines. * The site is very large and there is a chance for the web crawlers to overlook some of the new or recently updated content * When websites have a huge number of pages that are isolated or not well linked together, or * When a website has few external links

CONTENTS

* 1 History

* 2 File format

* 2.1 Element definitions

* 3 Other formats

* 3.1 Text file * 3.2 Syndication feed

* 4 Search engine submission

* 4.1 Limitations for search engine indexing

* 5 Sitemap limits * 6 Multilingual and multinational Sitemaps * 7 See also * 8 References * 9 External links

HISTORY

Google
Google
first introduced Sitemaps 0.84 in June 2005 so web developers could publish lists of links from across their sites. Google, MSN and Yahoo
Yahoo
announced joint support for the Sitemaps protocol in November 2006. The schema version was changed to "Sitemap 0.90", but no other changes were made.

In April 2007, Ask.com and IBM announced support for Sitemaps. Also, Google, Yahoo, MS announced auto-discovery for sitemaps through robots.txt. In May 2007, the state governments of Arizona, California, Utah and Virginia announced they would use Sitemaps on their web sites.

The Sitemaps protocol is based on ideas from "Crawler-friendly Web Servers," with improvements including auto-discovery through robots.txt and the ability to specify the priority and change frequency of pages.

FILE FORMAT

The Sitemap Protocol format consists of XML
XML
tags. The file itself must be UTF-8 encoded. Sitemaps can also be just a plain text list of URLs. They can also be compressed in .gz format.

A sample Sitemap that contains just one URL and uses all optional tags is shown below.

http://example.com/ 2006-11-18 daily 0.8

The Sitemap XML
XML
protocol is also extended to provide a way of listing multiple Sitemaps in a 'Sitemap index' file. The maximum Sitemap size of 50 MiB or 50,000 URLs means this is necessary for large sites.

An example of Sitemap index referencing one separate sitemap follows.

http://www.example.com/sitemap1.xml.gz 2014-10-01T18:23:17+00:00

ELEMENT DEFINITIONS

The definitions for the elements are shown below:

ELEMENT REQUIRED? DESCRIPTION

Yes The document-level element for the Sitemap. The rest of the document after the '' element must be contained in this.

Yes Parent element for each entry.

Yes The document-level element for the Sitemap index. The rest of the document after the '' element must be contained in this.

Yes Parent element for each entry in the index.

Yes Provides the full URL of the page or sitemap, including the protocol (e.g. http, https) and a trailing slash, if required by the site's hosting server. This value must be shorter than 2,048 characters. Note that ampersands in the URL need to be escaped as .

No The date that the file was last modified, in ISO 8601 format. This can display the full date and time or, if desired, may simply be the date in the format YYYY-MM-DD.

No How frequently the page may change:

* always * hourly * daily * weekly * monthly * yearly * never

"Always" is used to denote documents that change each time that they are accessed. "Never" is used to denote archived URLs (i.e. files that will not be changed again).

This is used only as a guide for crawlers , and is not used to determine how frequently pages are indexed.

Does not apply to elements.

No The priority of that URL relative to other URLs on the site. This allows webmasters to suggest to crawlers which pages are considered more important.

The valid range is from 0.0 to 1.0, with 1.0 being the most important. The default value is 0.5.

Rating all pages on a site with a high priority does not affect search listings, as it is only used to suggest to the crawlers how important pages in the site are to one another.

Does not apply to elements.

Support for the elements that are not required can vary from one search engine to another.

OTHER FORMATS

TEXT FILE

The Sitemaps protocol allows the Sitemap to be a simple list of URLs in a text file. The file specifications of XML
XML
Sitemaps apply to text Sitemaps as well; the file must be UTF-8 encoded, and cannot be more than 10 MB large or contain more than 50,000 URLs, but can be compressed as a gzip file.

SYNDICATION FEED

A syndication feed is a permitted method of submitting URLs to crawlers; this is advised mainly for sites that already have syndication feeds. One stated drawback is this method might only provide crawlers with more recently created URLs, but other URLs can still be discovered during normal crawling.

It can be beneficial to have a syndication feed as a delta update (containing only the newest content) to supplement a complete sitemap.

SEARCH ENGINE SUBMISSION

If Sitemaps are submitted directly to a search engine (pinged ), it will return status information and any processing errors. The details involved with submission will vary with the different search engines. The location of the sitemap can also be included in the robots.txt file by adding the following line: Sitemap:

The should be the complete URL to the sitemap, such as: _http://www.example.org/sitemap.xml_

This directive is independent of the user-agent line, so it doesn't matter where it is placed in the file. If the website has several sitemaps, multiple "Sitemap:" records may be included in robots.txt, or the URL can simply point to the main sitemap index file.

The following table lists the sitemap submission URLs for several major search engines:

SEARCH ENGINE SUBMISSION URL HELP PAGE MARKET

Baidu
Baidu
HTTP://ZHANZHANG.BAIDU.COM/DASHBOARD/INDEX Baidu
Baidu
Webmaster Dashboard China, Hong Kong, Singapore

Bing (and Yahoo! ) HTTP://WWW.BING.COM/WEBMASTER/PING.ASPX?SITEMAP= Bing Webmaster Tools Global

Google
Google
HTTP://WWW.GOOGLE.COM/WEBMASTERS/TOOLS/PING?SITEMAP= Submitting a Sitemap Global

Yandex HTTP://WEBMASTER.YANDEX.COM/SITE/MAP.XML Sitemaps files Russia, Ukraine, Belarus, Kazakhstan, Turkey

Sitemap URLs submitted using the sitemap submission URLs need to be URL-encoded , for example: replacing : (colon) with %3A, / (slash) with %2F.

LIMITATIONS FOR SEARCH ENGINE INDEXING

Sitemaps supplement and do not replace the existing crawl-based mechanisms that search engines already use to discover URLs. Using this protocol does not guarantee that web pages will be included in search indexes, nor does it influence the way that pages are ranked in search results. Specific examples are provided below.

* Google
Google
- Webmaster Support on Sitemaps: "Using a sitemap doesn't guarantee that all the items in your sitemap will be crawled and indexed, as Google
Google
processes rely on complex algorithms to schedule crawling. However, in most cases, your site will benefit from having a sitemap, and you'll never be penalized for having one." * Bing - Bing uses the standard sitemaps.org protocol and is very similar to the one mentioned below. * Yahoo
Yahoo
- After the search deal commenced between Yahoo! Inc. and Microsoft, Yahoo! Site Explorer has merged with Bing Webmaster Tools

SITEMAP LIMITS

Sitemap files have a limit of 50,000 URLs and 50MiB per sitemap. Sitemaps can be compressed using gzip , reducing bandwidth consumption. Multiple sitemap files are supported, with a Sitemap index file serving as an entry point. Sitemap index files may not list more than 50,000 Sitemaps and must be no larger than 50MiB (52,428,800 bytes) and can be compressed. You can have more than one Sitemap index file.

As with all XML
XML
files, any data values (including URLs) must use entity escape codes for the characters ampersand (">

* ^ M.L. Nelson; J.A. Smith; del Campo; H. Van de Sompel; X. Liu (2006). "Efficient, Automated Web Resource Harvesting" (PDF). _WIDM'06_. * ^ O. Brandman, J. Cho, Hector Garcia-Molina , and Narayanan Shivakumar (2000). "Crawler-friendly web servers". _Proceedings of ACM SIGMETRICS Performance Evaluation Review, Volume 28, Issue 2_. doi :10.1145/362883.362894 . CS1 maint: Multiple names: authors list (link ) * ^ _A_ _B_ _C_ _D_ _E_ _F_ _G_ " Sitemaps XML
XML
format". Sitemaps.org. 2016-11-21. Retrieved 2016-12-01. * ^ http://support.google.com/webmasters/bin/answer.py?hl=en&answer=183668 * ^ "About Google
Google
Sitemaps". Google.com. 2016-12-01. Retrieved 2016-12-01. * ^ "Multilingual and multinational site annotations in Sitemaps". _ Google
Google
Webmaster Central Blog_. Pierre Far. May 24, 2012.