nofollow

Nofollow is a statement within the HTML code that instructs search engines not to use back references to calculate the link popularity. The nofollow statement can be used in two ways: Firstly, as a microformat ( in full HTML notation rel = " nofollow" ) within hyperlinks on the other as a meta tag within the page header of a document. Not all search engines follow these instructions.

The deliberate lack of nofollow is advertised in search engine marketing with the terms Dofollow or "follow link".

  • 2.1 Other areas of application

Syntax

Hyperlink

A normal hyperlink, for example example.com on the side, has been awarded in the HTML code as follows:

example < / a> If the value for the nofollow rel attribute (of English relationship. Relationship, kinship ) is to be used, the hyperlink is supplemented as follows:

example < / a> With this method, individual links can be marked individually.

Meta

nofollow is a supplement to the so-called meta tag "robots " that can also contain a value " nofollow". This has an impact on all links of a website.

Origin, function and effect

The value " nofollow" for the rel attribute was introduced in 2005 by Google and adopted almost simultaneously by all major search engines ( Yahoo, MSN). The specification is intended to avoid the impact of spam.

Many spammers try to by them advertised websites to increase by frequent placement of their links link popularity or their PageRank value, and thereby improve the position of its website within the search results in search engines ( spamdexing ). Since such links are undesirable, is in many places where visitors can independently ( for example, comments on blogs ), automatically to all links added rel = " nofollow" attribute to links. The Articles marked as links are then not used by the search engines for the calculation of link popularity, an abuse is excluded.

Other areas of application

The use of nofollow can be useful in other cases, in addition to the marking of suspected link spam in which the tracking link is unwanted by search engine robots and would only cause unnecessary traffic. Examples are links that lead to print views or trigger evaluation and other feedback features. However, the behavior of the search engines are in terms of rel = " nofollow" different and some follow links with the attribute.

Standardization

The value nofollow is a non-standard extension of the rel attribute. The addition of author-defined values ​​, however, is valid in HTML 4.01 and XHTML 1.0 with it. The robots meta tag, however, is defined in the Robots Exclusion Standard.

Criticism

Critics of nofollow links that the evaluation result of the search engines is changed by the nofollows. They see this as a distortion that leads to the loss of explanatory power. The argument that it was not the task of individual web sites that promote or ensure the quality of search engine rating system is expressed both by critics and proponents. Critics argue, the website owner is not responsible for picking up the search engines the trouble of distinguishing between potential spam and desired links. Proponents use the same argument and explain that they do not see it as their duty to serve the search engines as a source to calculate the placement of external websites.

In what ways follow the popular search engines of the term, is cause for speculation, since it is not an effective barrier, but in practice only a recommendation. In particular, it can index the link target can not be effectively excluded.

Swell

  • Web Development
  • Internet
  • Google
  • Search Engine Optimization
341245
de