At this point, most of you probably understand how the rel=“canonical” tag addresses duplicate content. If not, here’s an explanation: http://googlewebmastercentral.blogspot.com/2009/02/specify-your-canonical.html
You may have a pagination situation on your category pages where you’ll have the same content listed in each subsequent page or maybe you’re just trying to increase the good quality signals on your website by telling Google which pages they should be considering for indexing. In mid September, Google released HTML link elements (rel=“next” and rel=“prev”) that will help address a series of pages that are paginated in sections that may pose duplicate content issues, much like the way canonical tags work. According to Google, using this mark up will tell the spiders to:
- Consolidate indexing properties, such as links, from the component pages/URLs to the series as a whole (i.e., links should not remain dispersed between page-1.html, page-2.html, etc., but be grouped with the sequence).
- Send users to the most relevant page/URL—typically the first page of the series.
The rel=“next” and rel=“prev” tags should only be used for pages with pagination that do not include a “view-all” page or if you’d like Google to prevent a “view-all” page from being shown.
In the case that a “view-all” page exists along with pagination, there are ways to optimize using the canonical tag. By default, Google will try to pick up “view-all” pages, but if you want to be more explicit about the page you’d like the focus on, Google tells us to “use rel=“canonical” from your component pages to your view-all to increase the likelihood that [they] will detect your series of pages appropriately.” http://googlewebmastercentral.blogspot.com/2011/09/view-all-in-search-results.html
To reiterate your options:
- Leave your pagination the way that it exists. Google will try to pick out the best page to serve up based on the search term whether you’ve used mark up such as the rel=“next”/rel=“prev” or not.
- If you prefer to have your view-all page show up in the search results, use the rel=“canonical” tag on the component pages in the paginated series.
- Use the rel=“next”/rel=“prev” tags on your component pages in the series to show a relationship and help Google more accurately index content.
Full instructions for options #2 and #3 are included in Google Webmaster Tools’ blog: http://googlewebmastercentral.blogspot.com/2011/09/pagination-with-relnext-and-relprev.html