We are running into issues with trying to figure out how to implement rel="next" and rel="prev" -- coupled with rel="canonical" -- with multiple sets of paginated content on the same page, with pages in multiple cultures. In other words, how do we implement these when we have a pager for both Product Reviews and Questions and Answers (aka "Q&A") on the same page, with duplicate content across culture-specific URLs (e.g. /us/en/my-product vs. /ca/en/my-product)?

Our current implementation will actually do a full postback when you click Page 2, and will add something to the query string (e.g. website.com/ca/en/my-product?previewpage=2 or website.com/ca/en/my-product?questionpage=2). If we only had one set of paginated content then the implementation would certainly be more straightforward. Adding a second set of paginated content (i.e. Q&A) complicates things.

Let's assume that we want the United States English page to be the canonical target (i.e. /us/en/my-product) based on culture. If you go to the /ca/en/my-product page you'll have a rel="canonical" href="/us/en/my-product". So far so good.

Let's also assume that we are not implementing a page that lists ALL Product Reviews and Q&A. This would likely solve a number of our problems by using rel="canonical" to this page, but is not an option for reasons that are out of scope for this discussion.

Now if you click on page 2 of Product Reviews, it will reload the page with /ca/en/my-product?reviewpage=2 as the URL. Given this scenario, here are my questions:

1. On page 2 of the my-product page on the Canadian site, should there be a rel="canonical" to /us/en/my-product?reviewpage=2 (assuming the content is identical in the United States and Canada)?
2. Should the rel="prev" go to /ca/en/my-product?reviewpage=1 or should it go to /ca/en/my-product ? The query-string version would really only be accessible if using the pager and shows the exact same content as the base page. The following two questions are closely related to this one.
3. Should the /ca/en/my-product?reviewpage=1 have a rel canonical directly to /us/en/my-product (United States page with nothing in query string) since the content is identical)?
4. Given that Q&A content is also paginated, should there be a rel="next" on the base page without query string? In other words, should the /ca/en/my-product page have a rel="next" to /ca/en/my-product?reviewpage=2 AND rel="next" to /ca/en/my-product?questionpage=2 . So far as I can tell it doesn't make sense to have multiple rel="next" implementations on the same page.

I suspect that the pages with query string values should have rel="next" and rel="prev" that only point to other pages with query strings and not to the base page. The ?reviewpage=1 and ?questionpage=1 pages would then just have a rel="canonical" to /us/en/my-product .

Thoughts? I know this is a tough one -- that's why I brought it to this community. Thanks so much for your help in advance!