Canonical URL

To avoid situations in which two pages with identical content will be indexed on different URLs, one of the pages should be added a canonical tag and be defined as a canonical URL. The canonical URL is the authorized version of the page and it will be indexed by the search engines.

Examples of URL addresses with identical content:

 http://www.website.com

http://www.website.com/index.html

http://www.website.com/index?tracking-code