What is the function of the html "rel" attribute?

Question

I understand that rel got something to do with relationships between things (documents? elements?) but I don't really get anything past that. What exactly does it do when used in the achor tag ? Also, are there specific values for x in rel="x"?

Answer 1

Typically they are used to provide information to search engines about the structure of your website. For instance, you can give links a next or prev rel attribute for paginating links (links which show the next/last set of search results); A nofollow to inform search engines not to crawl (this is also good for not passing SEO 'link juice' to external or low priority pages); Or you could supply a canonical value to tell search engines which is the default link for the page it is looking at (sometimes pages are accessible via a number of different links, and this avoids indexing of duplicate content which could hurt your SEO).

This describes only a few possible uses - it is a very versatile tag.

With regards to navigation, pagination and canonicalization, here are couple of useful links from Google:

https://web.archive.org/web/20180125083221/https://support.google.com/webmasters/answer/1663744

https://support.google.com/webmasters/answer/139394

Answer 2

it specifies the relationship between the current document and the linked document.

here you can find a good reference: http://reference.sitepoint.com/html/a/rel

and this was helpfull to me too

http://www.falsepositives.com/index.php/2009/03/24/html-tags-and-rel-attributes-you-really-should-know/

Regards

Answer 3

the rel attribute links files such as CSS(cascading Stylesheets) JS(Javascript), and other indexed files to its sources.

For example if I wanted to link a stylesheet to my index.html

I would type

 <link rel="stylesheet" href="style.css" type="text/css" media="all" />

Answer 4

Let's see some examples of possible values of rel, which indicates the relationship between the href page(linked document) and the actual page:

<a href="http://creativecommons.org/licenses/by/2.0/" rel="license">cc by 2.0</a>

Here the page indicates that the destination of that hyperlink is a license for the current page

<a rel="directory" href="http://dmoz.org/Computers/Internet/">Computers/Internet</a>

In this one the page indicates that the destination of the hyperlink is a directory listing containing an entry for the current page.

Check more at http://microformats.org/wiki/rel-faq#How_is_rel_used