Google, Yahoo, and Microsoft have announced support for a new tag to help reduce duplicate content issues. One source of duplicate content is when the same web page can be accessed from multiple URLs. The new canonical link tag specifies what is the preferred URL for the webpage. While search engines will use this as strong hint, they will use algorithmic mechanisms to compare the URLs to deal with improper use or abuse of the tag. The URL must be on the same domain, but can be on a different subdomain and can use relative or absolute URLs. The tag should be in the following format: <link rel=”canonical” href=”http://www.example.com” /> and should be placed in <head> section of the webpage. Google currently supports the tag, Yahoo says that it will implement support “over the coming months”, and Microsoft says that it will provide “full support in one of our upcoming releases.”