Nofollow tag writing and introduction to nofollow usage

Whether you are building external links for websites or exchanging friendly links, you will inevitably encounter a problem, that is, the nofollow tag. The literal meaning of Nofollow is not to track, it is an html tag value, the purpose is to tell search engines spider not to track a specific link on the page.

The nofollow tag is a tag proposed by Google, Yahoo and Microsoft in the past few years. After the link is added to this tag, the weight will not be calculated. Search engines support the nofollow attribute, which greatly suppresses spam messages in blogs or forums. This is a great thing for the webmaster.

nofollow is a value of the content attribute of HTML meta tag (meta) and the rel attribute of the link tag (a). It tells the machine (crawler) that there is no need to track the target page. In order to fight blogspam (blog spam message information), Google recommends nofollow to tell search engines that crawlers do not need to crawl the target page, and at the same time tells search engines that do not need to pass the pagerank of the current page to the target page. However, if you submit the page directly through sitemap, the crawler will still crawl. The nofollow here is just an attitude of the current page toward the target page, and does not represent the attitude of other pages toward the target page.

There are two uses of nofollow:

1. Used for meta meta tags: <meta name=robots content=nofollow />, telling the crawler that all links on this page do not need to be tracked.

2. Used for a tag: <a href=login.aspx rel=nofollow>Login</a>, telling the crawler that the page does not need to be tracked.

nofollow has three main functions:

1. Prevent untrustworthy content. The most common thing is spam links in spam messages and comments on the blog to obtain external links, and to prevent the page from pointing to some spam pages and sites.

2. Paid links: In order to prevent paid links from affecting Google's search results ranking, Google recommends using the nofollow attribute.

3. Guide crawlers to crawl effective pages: Avoid crawlers to crawl some meaningless pages, which affects the efficiency of crawlers to crawl.

In order to maximize the optimization of search engines, some SEOs can control the flow of PR through nofollow, which can optimize some specific pages well. Of course, this optimization is more suitable for some old sites that have accumulated a considerable number of PRs. In order to prevent the abuse of PR pruning and nofollow, Google has weakened the role of nofollow. The previous nofollow not only did not cause PR flow, but also did not cause PR losses. Although the current nofollow regulations will not cause PR to flow to the target page, the original target page will be lost. For example, the current page PR is 1, and there are 10 links on the page, one of which is a nofollow link. According to the previous nofollow regulations, each non-nofollow link points to a target page will get a 1/9 PR. The link containing nofollow cannot get a PR. According to Google's new regulations on nofollow, the target page pointed to by non-nofollow links can only get 1/10, and the nofollow link also cannot get a PR, which means that 1/10 PR is lost.

The role of nofollow in Google is already very weak, so SEO needs to control the flow of PR on the site and avoid links pointing to spam pages. It can only rely on manual review methods.

Let’s first look at an example, the way to write nofollow tags, take my blog as an example:

A normal A tag is as follows: