Resolving Duplicate Content Issues
Duplicate content represents a substantive issue for web publishers, because websites cannot get top placements in the search results by using content which can be find on other web pages.
Duplicate content can also be penalised by search engines.
The Canonical Tag
The Canonical Tag (rel=”canonical”) tells Google, Yahoo and Bing that there is duplicate content on a page.
Not all duplicate content is bad content. Sometimes web publishers want to post content from other partner websites and blogs, or to exchange articles, etc.
In order to tell the search engines that the respective content is not bad duplicate, the canonical tag shows the URL, the link source of the original content.
Users can’t see the URL, just the search engines.
The canonical tag representation:
<link rel=”canonical” href=”URL” />
The link source in the canonical tag will not redirect users to the page where the original content is located. This is solely for the search engines, and cannot be seen by the website users.
An important mention is that the canonical tag is not a 301 redirect.
A 301 redirect sends search engine bots and website users, to the link source.
Iframes are pretty different than the canonical tags, because the search engine bots(spiders) cannot “see”(crawl) the content embeded in an iframe, thus the respective content won’t be indexed.
How this works?
The content from the original URL will be placed on the page of your choice, like a picture.
The main use of this technique is to control the flow of the link juice(authority and trust given by a page to another), by lowering the number of crawlable links presented on a certain page.
Some web publishers hide duplicate text content in images, because search engines cannot crawl images for informations.
Search Engine Optimisation Expert
Seaside Software Team
Nottingham, United Kingdom