A possible way for search engine optimization

These days, we talked a lot about how to make search engine optimization. Recently I read some articles and they mentioned a tenique named”nofollow”, which may be of interest.

nofollow is an HTML attribute value used to instruct some search engines that a hyperlink should not influence the link target's ranking in the search engine's index. It is intended to reduce the effectiveness of certain types of search engine spam, thereby improving the quality of search engine results and preventing spamdexing from occurring in the first place.

Through the definition, we know that “nofollow” provides website administrators a way to inform search engine not to track the link on the web page or a particular link. Primly, the attribute of nofollow appears in meta tag of web page to tell search engine not to crawl all links. For example,
(meta name="robots" content="nofollow")

Before the using nofollow on a link, search engine, like google, does a lot of work to prevent the crawler to track this link. (For example, redirecting the link to addresses listed in robots.txt, which contains all the addresses prevented). Google creates “ rel” attribute whose value is nofollow in order to make website administrator control page more precisely: indicate crawler not to follow the link to the page being linked to.
(a href="signin.php" rel="nofollow")sign in(/a)

How does google manipulate those links tagged with nofollow? It does not catch the PageRank or pitch information from those links. In other word, using nofollow will let google give up those targets’ links. However, if other web sites do not use “nofollow” to tag those targets or the addresses of those targets are submitted through some particular org, like Sitemap, the targets’ web page will still possibly be indexed by google. In this case rel="nofollow" actually tells a search engine "Don't score this link" rather than "Don't follow this link."
Anyway, we can use nofollow in the following scenario:
* Distrustful content: If we don’t want to provide guarantee of safety for links appearing on your web page (for example, signatures, comments and partner links left behind by distrustful customers.), you should tag them as nofollow. By this way, we can keep away Spam information coming from those distrustful website.
* Charge link: the pagerank of a website in google, partly lies on the analysis of links in that website. In order to avoid bad effect of charge link, which will consequently affect user in a unhappy way, “nofollow “ is also recommended.
There are many other cases in which nofollow can be put to good use. However, please use it wisely and dont try to manipulate google PR algorithm by using this way, because “the next google algorithm update may penalize Websites for over excessive use of rel="nofollow" ”.
If you want to know it more with regard to search engine optimization, you can click here “Search Engine Optimization for Site Owners and Small Businesse”