The rel attribute is used to describe the relationship between the link and the page containing the link, as well as the Link Opening target. It has many attribute values, such as next, previous, chapter, and section. For more information, see the application of rel = 'external nofollow' and rel = 'nofollow. This is a rel = 'nofollow' attribute added by Google to cope with spam links. This attribute was subsequently widely used by various search engines. Rel = 'external nofollow' is more standard than rel = 'nofollow.
Rel = 'external nofollow' and rel = 'nofollow' their functions are as follows: Chinese translation "do not read" and "Do not read external links". This is clear.
However, some people have mentioned recently that rel = 'external 'does not know what it means, and whether this attribute is the same as rel = 'external nofollow' and rel = 'nofollow.
Actually, rel = 'external 'is only an attribute that replaces target = "_ blank. The attribute of target = "_ blank" is to open a new window. However, some blogs are well known for their strict doctype.Source codeIn the first line, you can see: <! Doctype HTML public "-// W3C // dtd xhtml 1.0 strict // en" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> in this case, target = "_ blank" may become invalid, therefore, the rel = 'external 'parameter is used instead.
Therefore, the properties of rel = 'external 'only serve to open a new window.