Duplicate content is the nightmare of every webmaster. Many webmasters are always afraid of the content theft; the reason is when Google finds it will penalize them for having duplicate content on their site.

Quite often webmasters get nervous about the duplicate content on the different pages of their sites, although they are not at all responsible for it.

Canonical SEO Strategy

Such thing often happens with the dynamic pages whose contents can be viewed via different URLs due to change in things like  parameters, category navigation, tracking id or session id and, which are beyond the control of webmasters.

To overcome this problem major search engines like Google, Yahoo! and MSN has come up with the solution i.e. using a simple tag, known as canonical tag. One of the most important developments on the web has been the addition of canonical link elements.

This element, rendered as part of the HTML making up a link is seen as: rel=”canonical”, and is in place to help prevent the issue with the duplicate content.

How To Use Canonical?

The webmaster can add the rel=”canonical” link to the head <head> section of a non-canonical version of each HTML page.

Here is an example of a complete canonical URL:

<link rel=”canonical” href=”http://www.example.com/category/product</a>

Using rel=’canonical’ tag allows the search engine crawlers to determine which page is the original content and therefore would be ranked higher. Product pages can often involve more than one page relating to the single product, thus result in more than a single page containing the same content. Using rel=’canonical’ can easily solve this issue.

Sometimes you can make use of  Robots.txt file to block some content of your site, so that search engine does not consider as the duplicate content. You can also make use of ‘noindex’ tags to prevent some pages to get index in the search engines. Both the ‘noindex’ and ‘nofollow’ tags can be placed on either the page or the link level.

Using canonical link is a great way to deal with duplicate content issue. However, There may be times to use other approaches, but when in doubt, adding this link element is a safe and good SEO strategy.