Shrushti – SEO blog

Google: Cross-Domain Canonical Tag This Year

Duplicate content is a common occurrence on the web and in many cases can hurt search engine rankings. While the search engines may not always technically penalize webmasters for duplicate content, there are still a lot of ways it can hurt.

WebProNews is covering the Search Marketing Expo (SMX) East in New York, where representatives from the three major search engines (Google, Yahoo, and Bing) discussed how their respective web properties handle duplicate content issues. Following are some takeaways from each.

Duplicate Content in Google

Duplicate Content on Google – Joachim KupkeThe way Google handles duplicate content has been discussed a lot in recent memory. This is largely due to a video Google’s Greg Grothaus uploaded, in which he discusses at length, the way Google handles a variety of different elements of the duplicate content conversation.

Joachim Kupke, Sr. Software Engineer of Google’s Indexing Team reiterated much of what Grothaus said. He also said that Google has a ton of infrastructure for content duplication elimination:

- redirects
- detection of recurrent URL patterns (the ability to ‘learn’ recurrent url patterns to find duplicated content)
- actual contents
- most recently crawled version
- earlier content
- contents minus things that don’t change on a site

Kupke said to avoid dynamic URLs when possible (although Google is “rather good” at eliminating dupes). If all else fails, use the canonical link element. Kupke calls this a “Swiss Army Knife” for duplicate content issues.

Google says the canonical link element has been tremendously successful. It didn’t even exist a year ago, and is has grown exponentially. It has had a huge impact on Google’s canonicalization decisions, and 2 out of 3 times, the canonical tag actually alters the organic decision in Google.

Google says a common mistake is designating a 404 as canonical, and this is typically caused by unnecessary relative links. So, avoid changing rel=”canonical” designations, and avoid designating permanent redirects as canonical.

Also, do not disallow directives in robots.txt to annotate duplicate content. It makes it harder to detect dupes, and disallowed 404s are a nuisance. There is an exception however, and that is that interstitial login pages may be a good candidate to “robot out,” according to Kupke.

Kupke says that canonical works, but indexing takes time. “Be patient and we WILL use your designated canonicals.” Cleaning up an existing part of the index takes even longer, and this may leave dupes serving for a while despite rel=canonical, Kupke adds.

At SMX, Google announced that cross domain rel=canonical is coming within this year. So for example, if the Chicago Tribune has an article on the New York Times, and the rel=canonical points to the Chicago Tribune then Google will only credit the Chicago Tribune with the content.

Duplicate Content in Bing

Sasi Parthasarathy

As far as how Bing views duplicate content, intention is key. If your intent is to manipulate the search engine, you will be penalized.

Sasi Parthasarathy, Program Manager of Bing says to consolidate all versions of a page under one URL. “Less is more, in terms of duplicate content.” If possible, use only one URL per piece of content.

Bing isn’t supporting the canonical link element (as a ranking factor) yet, but it is coming. They do say to use it, but it’s just not really a ranking factor in Bing yet. Bing says that there has been an increase in the usage of canonical tags in the past 6 months, but adoption issues still exist. According to Parthasarathy, 30% of canonical tags point to the same domain (which is fine), and 9% use it to point to other domains. This could be a mistake or it could be manipulative. Bing says they will look for other factors to try and determine which it is.

Bing says canonical tags are hints and not directives. “Use it with caution,” and not as an alternative to good web design.

With regards to www vs non-www, just pick one and stick with it consistently. Remove default filenames at the end of your URLs. Bing also says 301 redirects are your best friend for redirecting, use rel=”nofollow” on useless pages, and use robots.txt to keep content you don’t want crawled out.

Duplicate Content in Yahoo

Cris Pierry

If everything goes according to plan, you’re going to need to worry about how Bing handles duplicate content if you’re worried about how Yahoo handles it, but Yahoo’s Cris Pierry, Sr. Director of Search, offered a few additional tips.

Pierry says descriptive URLs should be easily readable, and it’s not a good idea to change URLs every year. In addition, use canonical, avoid case sensitivity, and avoid session IDs and parameters.

Pierry also says to use sitemaps, and submit them to Yahoo Site Explorer. Improve indexing by proper robots.txt usage, and use Site Explorer to delete URLs that you dont’ want Yahoo to index. Finally, provide feeds to Yahoo Site Explorer, and report spam sites linking to you in Site Explorer.

Yahoo says metadata and SearchMonkey are enhancing presentation.

Source: http://www.webpronews.com/topnews/2009/10/05/duplicate-content-on-google-bing-yahoo

Hi Folks,

If you attend any marketing classes during your graduation, you definitely read about 4 P’s of Marketing.

1) Placement

2) Promotion

3) Price

4) Product

Dr. Pete writes a good article on 4 Rs of SEO :

1) Robots

2) Rankings

3) Relevance

4) Results

Have a look at this article, I think its great if you want to get some theory kind of  knowledge :  4R of SEO

So, Now if you are going to read the article please share your view on or blog in form of comments.

All three major search engines announced today “Canonical Tag” for resolving Canonical issue.

Lets What GoogleWebmaster Blog Says about this tag :

“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.”

You can put this link tag inside the <head> section of the duplicate content URLs:
<link rel=”canonical” href=”http://www.example.com/product.php?item=mywidgets” /> where URL is the original one which you want to show to search engines.

Below are the some common question related canonical queries from Google Webmaster Blog

Is rel=”canonical” a hint or a directive?
It’s a hint (not command) that we honor strongly. We’ll take your preference into account, in conjunction with other signals, when calculating the most relevant page to display in search results.

Can I use a relative path to specify the canonical, such as <link rel=”canonical” href=”product.php?item=swedish-fish” />?
Yes, relative paths are recognized as expected with the <link> tag. Also, if you include a <base> link in your document, relative paths will resolve according to the base URL.

Is it okay if the canonical is not an exact duplicate of the content?
We allow slight differences, e.g., in the sort order of a table of products. We also recognize that we may crawl the canonical and the duplicate pages at different points in time, so we may occasionally see different versions of your content. All of that is okay with us.

What if the rel=”canonical” returns a 404?
We’ll continue to index your content and use a heuristic to find a canonical, but we recommend that you specify existent URLs as canonicals.

What if the rel=”canonical” hasn’t yet been indexed?
Like all public content on the web, we strive to discover and crawl a designated canonical URL quickly. As soon as we index it, we’ll immediately reconsider the rel=”canonical” hint.

Can rel=”canonical” be a redirect?
Yes, you can specify a URL that redirects as a canonical URL. Google will then process the redirect as usual and try to index it.

What if I have contradictory rel=”canonical” designations?
Our algorithm is lenient: We can follow canonical chains, but we strongly recommend that you update links to point to a single canonical page to ensure optimal canonicalization results.

Can this link tag be used to suggest a canonical URL on a completely different domain?
No. To migrate to a completely different domain, permanent (301) redirects are more appropriate. Google currently will take canonicalization suggestions into account across subdomains (or within a domain), but not across domains. So site owners can suggest www.example.com vs. example.com vs. help.example.com, but not example.com vs. example-widgets.com.

Sounds great—can I see a live example?
Yes, wikia.com helped us as a trusted tester. For example, you’ll notice that the source code on the URL http://starwars.wikia.com/wiki/Nelvana_Limited specifies its rel=”canonical” as: http://starwars.wikia.com/wiki/Nelvana.

The two URLs are nearly identical to each other, except that Nelvana_Limited, the first URL, contains a brief message near its heading. It’s a good example of using this feature. With rel=”canonical”, properties of the two URLs are consolidated in our index and search results display wikia.com’s intended version.

A yahoo Perspective

Yahoo search blog says that it is a way to fight duplication.

A few technical details:

• The URL paths in the <link> tag can be absolute or relative, though we recommend using absolute paths to avoid any chance of errors.

• A <link> tag can only point to a canonical URL form within the same domain and not across domains. For example, a tag on http://test.example.com can point to a URL on http://www.example.com but not on http://yahoo.com or any other domain.

• The <link> tag will be treated similarly to a 301 redirect, in terms of transferring link references and other effects to the canonical form of the page.

• We will use the tag information as provided, but we’ll also use algorithmic mechanisms to avoid situations where we think the tag was not used as intended. For example, if the canonical form is non-existent, returns an error or a 404, or if the content on the source and target was substantially distinct and unique, the canonical link may be considered erroneous and deferred.

• The tag is transitive. That is, if URL A marks B as canonical, and B marks C as canonical, we’ll treat C as canonical for both A and B, though we will break infinite chains and other issues.

Thanks Google, Yahoo and Live For Helping Us Via One more Accidental Panelty Which occurs by you.

I think its very easy for us (dynamic product driven site owners) to specify a URL for search engines.

Happy SEO and Time to say GoodBye to Canonical

Technorati Tags: Canonical Url, Canonical Link Tag, Canonical Hint, Canonical Support, Canonical Issue