Comprehensive analysis of the function of nofollow tag in SEO

This article from five knowledge points to comprehensively analyze the nofollow label how to use and nofollow label writing: First, what does nofollow mean. Second, nofollow the use of property labels. Third, rel nofollow the correct writing format. The application field of nofollow. V: What is nofollow and noindex.

Before the analysis to say Sina, netease two big portal blog to prevent malicious spamming blog outside the chain adopted nofollow label, Sina blog Nofollow existed before, but now I see and did not add nofollow tag in the blog, but NetEase blog is now indeed added rel= "nofollow" nofollow label, we do not need to send NetEase blog. The following five major aspects of the overall resolution of the nofollow tag.

First, what does nofollow mean?

Nofollow is the property value of an HTML tag. Its presence provides webmasters with a way to tell the search engine to "do not track links on this page" or "do not track this particular link." The meaning of this tag is to tell the search engine that the link is not edited by the author itself, so this link is not a trust ticket.

Nofollow attribute Introduction: Usually, the reverse link is to pass the weight, so some do SEO in order to add backlinks, in forums and blogs and so on a large number of publications with unrelated links content. The existence of these spam links to the search engine on the quality of the Web site to cause a certain degree of trouble.

Therefore, in this case, nofollow is just a few major search engine business (for example, Google, Yahoo, Baidu, etc.) in order to deal with the garbage link (Spam) introduced a property.

At present, most of the blog and build the station system has been added nofollow attribute. In other words, it is often futile to leave links on other people's blogs to get PR values, especially for celebrity bloggers, with nofollow tags.

However, it is worth noting that the site added the nofollow attribute tag does not mean that the search engine does not include that link, just do not calculate into the reverse link. In fact, it can achieve the purpose of attracting spiders crawling your site, but it does not give you the weight of the site passed. If you are also worried about Web sites being harassed by spam, the Nofollow property is a very good "junk link Firewall".

Second, the use of Nofollow property labels

We have an example to understand the Nofollow property: If a page has a link to the B page, but the a page to the link with the rel= "nofollow" annotation, then the search engine will not be a page to calculate into the reverse Link b page.

How do you use nofollow tags? For example, there is a comment on a blog:

<a href= "http://" >seo ">www.xxx.com" >seo optimization </a>

If you do the following, you add the nofollow tag:

<a href= "http://www.xxxx.com" rel= "nofollow" >seo optimization </a>

When the search engine calculates the weight of the site, it does not take this link into account.

Third, the correct writing format of rel nofollow

Rel= "nofollow" attribute, is written in a tag inside, the position can be in front, also can in after.

The application field of nofollow

1. nofollow application in the blog, forum message, used to screen the transfer of weight.

Nofollow mainly used in user messages, such as not subject to control of the site, these places vote is not the will of the webmaster, told the search engine do not give him a vote is appropriate.

Some speculative, improper webmaster in with others to do friendship Link, will others anchor text use nofollow, shielding off the transfer of weight, such practice is not kind.

2. Nofollow control station weight.

For example, in the station reasonable application nofollow attribute, will help the reptile to save a lot of time, but also can let the crawler more crawl those has the value of the page. For example: the website contact us, about us, the privacy protection, the website backstage, the registration page and so on the link, these links are not included the value also does not have the rank. When these unimportant pages are placed on the Nofollow property, the crawler does not crawl, and then crawls the links without nofollow attributes. In this way, you save the reptile time (the total time that the reptile stays on your site is relatively fixed during a certain period). Then, you can also "control" crawler crawl important pages, so that some have not been crawled by the Crawler good page has been included in the opportunity. Although the crawler may not be able to crawl through all of your pages, but has improved too much. In particular, the site of these unimportant pages nofollow off, the first page of the PR value and weight will not be passed to them.

Five, what is nofollow and noindex

These two tags are used in the <meta name= "Robots" content= "Nofollow,noindex", and the site keyword and description are placed inside the head tag, To mask the search to crawl the current page and the current page export all links, including inbound links and outbound links. But here I want to say after the experiment, some search engines do not follow this nofollow tag usage very much. This article from http://www.seo1912.com/sousuo/17.html, please respect others copyright, reprint please indicate the source.