Avoiding Duplicate Content: New Link Tag

Posted on 13. Feb, 2009 by Julius.

Google, Yahoo and Live.com have teamed up to fight duplicate content. For that matter they introduced a new link tag. As it is just a suggestion it will not completely fight the problem revolving around duplicate content but it will greatly decrease it.

Not only will the new link tag help in fighting duplicate content but it will also probably increase your web site’s link popularity. Why is that? Let’s take a look at an example.

Suppose most visitors visit your web site via http://yourwebsite.com/ . Others might also visit your blog via http://www.yourwebsite.com/ . Until today search engines might have seen these addresses as two different sites and thus your link popularity might have been split into half.

The new link tag Google, Yahoo, and Live.com introduced will help fight exactly these problems. Let’s look at another example to make it even clearer. Say you have a website with lots of products on it and the link to the product page looks like this one:

http://yourwebsite.com/product.php

Now when you look at fish as a product its URL might be the following one:

http://yourwebsite.com/product.php?item=fish

As you look around your page and search through the different categories you find a link back to your fish products.

http://yourwebsite.com/product.php?item=fish&id=101&type=food

This link refers you to the exact same page but through a different URL. Now to avoid this being taken as duplicate content you could just add the link tag to your page header:

<link rel="canonical" href="http://yourwebsite.com/product.php?item=fish" />

This simply specifies your preferred version and will keep search engines from mistaken your two URLs referring to the same content as duplicate content.

If you want to add this link tag to every page Joost from Yoast.com has already created a plug in that does exactly that.

1. Google Duplicate Content Penalty
2. What is Unique Content?