A rel="external" attribute value informs search engines that the link is on a domain that is outside the current website.
This is mostly used when including a link that is outside the web server.
Two <a> elements with an rel="external" attribute.
The links reference pages from an external server (domain).
The development of Impressionism in the visual arts was soon followed by analogous styles in other media that became known as impressionist music and impressionist iterature.
<p>
The development of Impressionism in the visual arts was soon
followed by analogous styles in other media that became known as
<a rel="external" target="_blank"
href="https://en.wikipedia.org/wiki/Impressionism_in_music">impressionist music</a> and
<a rel="external" target="_blank"
href="https://en.wikipedia.org/wiki/Impressionism_(literature)">impressionist iterature</a>.
</p>
The rel attribute defines the relationship between the current page and the linked page or resource.
rel="external" instructs search engines that the link is outside the current website.
It also allows CSS attribute selectors to style external links so they look different from local links.
<tagname rel="external" />
These elements accept the external value on the rel attribute.
| Elements | Description | |
|---|---|---|
| <a> | Specifies an anchor link -- see example above | |
| <area> | Creates clickable areas inside an image map. | |
| <form> | Specifies an HTML form. |
Here is when rel support started for each browser:
 Chrome
|
6.0 | Sep 2010 |
 Firefox
|
4.0 | Mar 2011 |
 IE/Edge
|
12.0 | Jul 2015 |
 Opera
|
11.1 | Mar 2011 |
 Safari
|
5.0 | Jun 2010 |
