Google, Yahoo and Live Search have introduced a new canonical link tag in order to allow website owners to better mark duplicate or near duplicate content :-
< link rel="canonical" href="the_real_lurl" >
Duplicate content, or near duplicate content occurs almost everywhere in an online store. For example, choosing a different currency for a product will result in near duplicate content, where only the price is different and the rest of the content is the same. Changing the sort order of a product listing results in near duplicate content and the list goes on and on...
Now there is a way to tell the search engines that they are looking at a page which is a duplicate or near duplicate of another page.
We are confident we have tagged the majority of duplicate content in the store. It is still to early to tell if we have tagged all of it.
Please feel free to contact us with any questions you may have.