As you know, Google is adjusting his algorithm nearly every day to generate the most opportune results for search queries by default. Generously they gave us hints how we should act to prevent bad results for our websites.
Especially since “Panda” was rolling out, every webmaster was anxious to avoid any kind of issues with content. But in some cases you can´t really prevent duplicate or near duplicate content, even if multiple websites using the same content. At this point I want to mention about a few measures to help Google to avoid duplicate.
Canonical-tag my #1
The canonical tag was rolling out by Google to help using the right URL for indexation and to avoid duplicate content. It is advisable for URLs which generate additional parameters. The implementation takes place inside the head <head> as a new link-tag.
get the following canonical tag:
<link rel=”canonical” href=http://www.domain.com/products.html />
Hreflang my #2
In 2011 Google has announced a new markup “hreflang” which helps websites with multilingual content to rank on their region. For instance, If websites using sub domains or different TLD to show content that is translated or provided for multiple geographic regions, then its recommend to use the “hreflang” markup. The implementation (with ISO 639-2) takes place in additional to the canonical-tag inside the head <head> as a new link-tag.
Two sites with the same (translated) content:
On 1) adding the following link-element:
<link rel=”alternate” hreflang=”en–gb” href=”http://www.domain.co.uk” />
On 2) adding the following link-element:
<link rel=”alternate” hreflang=”en–us” href=”http://www.domain.com” />
Cross-promoted content element my #3
To tagging duplicate website content you can also use the word cross-promoted additional with a link to the other website. It´s recommended using this content element at the start of your “original” text and at the end of your “duplicate” text. This action shows Google on an alternative way which content is the original. Just to make sure!
(author: Thomas Klein)