[wp-hackers] Canonical & Best Practices for Paged Comment

[Otto]

On Tue, Feb 17, 2009 at 11:21 AM, Mike Schinkel
<mikeschinkel at newclarity.net> wrote:
> Hi all:
>
>
> Now that it seems that rel="canonical" will make it into core, I've a question about how to best handle posts with paged comments. One option is to set the canonical URL to be the main post page that would include just the first set of comments but clearly the comments themselves are content and frequently we would like to see them indexed too. So what would be the best approach for this? As I ponder the options I can't come up with a good one, especially since Google doesn't like cloaked pages (i.e. one's that redirect for most people but not for Google's spiders.)
>
> Ideally if someone leaves a comment on page 2 with terms unique to other comments and also on in the post content that URL should show up somewhere in Google's index for those terms.
>
> Basically I'm just sending this email to hopefully trigger the discussion and/or to get a pointer to where it has already been discussed.

I think a lot of people are misunderstanding the idea behind the
rel=canonical and what it actually does and/or is used for. Having a
canonical link in your header does not stop Google from indexing the
page. It controls the URL that Google displays for search results.

>From this post on the topic:
http://googlewebmastercentral.blogspot.com/2009/02/specify-your-canonical.html

"we now support a format that allows you to publicly specify your
preferred version of a URL. If your site has identical or vastly
similar content that's accessible through multiple URLs, this format
provides you with more control over the URL returned in search
results. It also helps to make sure that properties such as link
popularity are consolidated to your preferred version."

If you were to use canonical on paged comments, then you'd probably
give the main permalink url to the post on all the comment pages. So,
Google would index all the pages, but any search hits for those pages
would give their result as the main post page, even if the match
occurred on one of the comments on a different comments page.

So your comments would still be indexed. It's just that the link in
the search results would now point to the main location for that post,
not to one of the comments pages for that post. All the pagerank for
all the comments pages would be consolidated to the main post page.
The duplicate content on all those comments pages (namely the post
itself) would get more or less ignored as being duplicate content,
since it's the same content on the same page.

All you're really doing is specifying that the URLs specifying comment
pages really are the same URL as the main post page, just sorta like
subpages of it.

-Otto