nofollow

Concept and specification - The 'nofollow' value was suggested to combat comment spam in blogs. - It was proposed by Google's Matt Cutts and Blogger's Jason Shellen in 2005. - The specification for 'nofollow' is copyrighted 2005-07 by the authors. - The value is subject to a royalty-free patent policy per the W3C Patent Policy. - It is also subject to IETF RFC 3667 & RFC 3668. Example and support - An example of a 'nofollow' link is: Link text. - Google announced in 2005 that 'nofollow' links would not influence PageRank. - Yahoo and Bing search engines also respect the 'nofollow' attribute. - In 2009, GoogleBot changed the way it treats 'nofollow' links to prevent PageRank sculpting. - As of March 2020, Google treats the 'nofollow' attribute as a hint for crawling and indexing. - The usage of 'nofollow' affects the distribution of PageRank among links. Interpretation by the individual search engines - Different search engines interpret 'nofollow' differently. - Google takes 'nofollow' literally and does not follow the link. - Yahoo! and Bing exclude 'nofollow' links from their ranking calculation. - Ask.com and Baidu also respect the 'nofollow' attribute. - The exact interpretation may vary between search engines. Use on other websites - MediaWiki software, used by Wikipedia, implemented 'nofollow' support in 2005. - Initially, the English Wikipedia used a URL blacklist instead of 'nofollow' in articles. - In 2007, 'nofollow' was added to article-space links on the English Wikipedia. - Other Wikimedia Foundation projects and external wikis are not affected by this policy. - Websites like Slashdot and social bookmarking sites use 'nofollow' selectively for user-submitted links. Qualified outbound links and related topics - Google introduced two ways to qualify outbound hyperlinks: rel=sponsored and rel=ugc. - rel=sponsored is used for links that are advertisements, sponsorships, or compensation agreements. - rel=ugc is used for user-generated content like comments and forum posts. - The attributes can be combined, such as rel=ugc sponsored. - WordPress plans to convert all blog comments into rel=ugc. - See also: noindex, PageRank, search engine optimization, web crawlers (search engine spiders), spam in blogs about nofollow, link building, blocking and excluding content from search engines (robots meta tag, robots exclusion standard - robots.txt). References: - The nofollow Attribute and SEO, archived from the original on 2011-07-15 - rel=nofollow Specification, Microformats.org, retrieved June 17, 2007 - W3C Patent Policy 20040205, W3.ORG - HTML 4.01 Specification, W3C.org, retrieved May 29, 2007 - Preventing comment spam, Official Google Blog, retrieved on May 29, 2007 Additional information: - Use rel=nofollow for specific links - Search Console Help - How Google, Yahoo & Ask.com Treat the No Follow Link Attribute - Search Engine Journal - Dofollow And Nofollow Links In SEO - Beta Compression - Webmasters. About Ask.com - Google Blog, Preventing comment spam - The Official Google Blog