Often times, you will see that a particular link has a rel attribute associated with it. Rel=”nofollow” is the most common usage whereby you tell Google and other search engines that a particular link is not to be “followed” and that pagerank must not be passed through that link.

But there are some other rel attributes which you should know, especially if you are working as an SEO or want to learn more about different rel attributes for links.

Before I list out all the rel attributes, let’s first try to understand what is a rel attribute and what does it actually mean.

What is a Rel Attribute?

The general syntax of a rel attribute is

<a rel=”nofollow” href=”https://www.domain.com”>This is a link</a>

The rel attribute defines the relationship between a linked resource and the current document. So in the above example, the rel attribute defines the relationship between the page which contains the link and the page which is linked to. In this case, the relationship is nofollow.

In specific links, the relationship could be different. It does not have to always be nofollow. In some links, it is possible that no relationship is defined at all. It is not a mandate that you always have to specify the relationship and that every link must contain a rel attribute. The rel attribute is optional and not a mandate.

In summary, the rel attribute defines the relationship between the source document and a target document. And the rel attribute can be part of other HTML elements, not just links. So the rel attribute it not limited to links but can also apply to other HTML elements like <form> or <nav> where it is necessary to pass on the “relationship” information to search bots, crawlers and spiders so they can understand what’s going on and how the different documents are related to each other.

Most Common Rel Attributes You Should Know

Below I have defined some of the most important and most common rel attributes you should know, and I have also explained the meaning of each attribute.

  1. Rel = “Nofollow” – It means that the target document is not to be crawled through the given link and you do not want to pass pagerank from your existing document. It is also a way of telling Google and other search engines – I do not endorse this link, but I am using it in my document for reference. It is not for endorsement or a citation, it is just a reference for others to see.
    Where is this used? – Hyperlinks.
  2. Rel = “Canonical” – It means that the target document is the master copy of the page. Whatever value is given in the rel canonical element, that is the master copy and that could be equal to the source document or different than the source document. This is used to prevent duplicate content issues.
    Where is this used? – In the head section of a given page.
  3. Rel = “ugc” – UGC stands for user generated content. This rel attribute is used in situations where the content is not created by the author of the page but created by other users reading the document. This could mean the comment section of blogs and forums or individual posts created by other users using the website. Any content that is user generated and not made by the author of that document can be marked as UGC.
    Where is this used? – It is used in hyperlinks where the content is user generated content and not by the author.
    Why is this important? – It is important to indicate user generated links and content to Google and other search engines because sometimes the website owner does not have complete control on what content shows up on the website, because part of it can be user generated (e.g forums, directory sites and other public platforms where anyone can register and create content.). So when Google and other search bots understand what section of a page is user generated content and what section is editorial in nature, they have a better clarity on what’s going on and that helps them rank the page in search results. It also helps the website owner avoid any sort of algorithmic penalty, because Google and other search engines know that the content is user generated in nature (so they sometimes may have a higher tolerance if it appears to be spammy and violates Google webmaster quality guidelines).
  4. Rel = “sponsored” – If someone else is paying you to manually link to them or there are paid advertisments in your page, you should always mark them as “sponsored”.

    Where is this used? – Hyperlinks.
    Why is this important?  – It is important to indicate Google and other search engines that you are explicitly telling them that this is a sponsored link and that it is not a natural editorial endorsement. When this clarity is given, search engines will understand what’s going on and that you are not doing any black hat things or accepting a fee in return of a link. However, if you don’t mention this explicitly and the search engines figure out that you’ve been selling links, then you would be in big trouble because you would be manually flagged by the web spam team and your website will lose it’s organic rankings.