Please note – I have found a better way of preventing this SEO duplicate content issue, which I have documented here: Add meta robots noindex to Magento review pages
If in your Magento product pages you’re pulling through review content, then you’ll want to ensure that the associated product reviews page isn’t available to search engines to eliminate the risk of duplicate content holding your website back in the search results pages.
After searching online for a number of solutions to this issue, including creating a custom module that extends the review/product and rewrite listAction method, we found a simple redirect rule to the long ID-based URL page works well. If you have canonical URLs enabled for single product pages, then search engines will be forgiving of this method as the page rendered at the non-search friendly URL also includes this canonical tag.
This code will work on any Magento install where the catalog product page matches this:
/catalog/product/view/id/000 (when SEO friendly URLs are disabled).
To implement this redirect, paste this code into your
.htaccess file in the server root and visit a review page to confirm that it is working correctly.
<IfModule mod_rewrite.c> RewriteRule ^review/product/list/id/(.*)$ /catalog/product/view/id/$1 [L,R] </IfModule>
Please let me know whether this works for you in the comments below.