Nearly 15 years ago, the nofollow attribute was introduced as a means to help fight comment spam. It also quickly became one of Google’s recommended methods for flagging advertising-related or sponsored links. The web has evolved since nofollow was introduced in 2005 and it’s time for nofollow to evolve as well.
Today, we’re announcing two new link attributes that provide webmasters with additional ways to identify to Google Search the nature of particular links. These, along with nofollow, are summarized below:

rel=”sponsored”: Use the sponsored attribute to identify links on your site that were created as part of advertisements, sponsorships or other compensation agreements.

rel=”ugc”: UGC stands for User Generated Content, and the ugc attribute value is recommended for links within user generated content, such as comments and forum posts.

rel=”nofollow”: Use this attribute for cases where you want to link to a page but don’t want to imply any type of endorsement, including passing along ranking credit to another page.

When nofollow was introduced, Google would not count any link marked this way as a signal to use within our search algorithms. This has now changed. All the link attributes — sponsored, UGC and nofollow — are treated as hints about which links to consider or exclude within Search. We’ll use these hints — along with other signals — as a way to better understand how to appropriately analyze and use links within our systems.
Why not completely ignore such links, as had been the case with nofollow? Links contain valuable information that can help us improve search, such as how the words within links describe content they point at. Looking at all the links we encounter can also help us better understand unnatural linking patterns. By shifting to a hint model, we no longer lose this important information, while still allowing site owners to indicate that some links shouldn’t be given the weight of a first-party endorsement.
We know these new attributes will generate questions, so here’s a FAQ that we hope covers most of those.

Do I need to change my existing nofollows?
No. If you use nofollow now as a way to block sponsored links, or to signify that you don’t vouch for a page you link to, that will continue to be supported. There’s absolutely no need to change any nofollow links that you already have.

Can I use more than one rel value on a link?
Yes, you can use more than one rel value on a link. For example, rel=”ugc sponsored” is a perfectly valid attribute which hints that the link came from user-generated content and is sponsored. It’s also valid to use nofollow with the new attributes — such as rel=”nofollow ugc” — if you wish to be backwards-compatible with services that don’t support the new attributes.

If I use nofollow for ads or sponsored links, do I need to change those?
No. You can keep using nofollow as a method for flagging such links to avoid possible link scheme penalties. You don’t need to change any existing markup. If you have systems that append this to new links, they can continue to do so. However, we recommend switching over to rel=”sponsored” if or when it is convenient.

Do I still need to flag ad or sponsored links?
Yes. If you want to avoid a possible link scheme action, use rel=“sponsored” or rel=“nofollow” to flag these links. We prefer the use of “sponsored,” but either is fine and will be treated the same, for this purpose.

What happens if I use the wrong attribute on a link?
There’s no wrong attribute except in the case of sponsored links. If you flag a UGC link or a non-ad link as “sponsored,” we’ll see that hint but the impact — if any at all — would be at most that we might not count the link as a credit for another page. In this regard, it’s no different than the status quo of many UGC and non-ad links already marked as nofollow.
It is an issue going the opposite way. Any link that is clearly an ad or sponsored should use “sponsored” or “nofollow,” as described above. Using “sponsored” is preferred, but “nofollow” is acceptable.

Why should I bother using any of these new attributes?
Using the new attributes allows us to better process links for analysis of the web. That can include your own content, if people who link to you make use of these attributes.

Won’t changing to a “hint” approach encourage link spam in comments and UGC content?
Many sites that allow third-parties to contribute to content already deter link spam in a variety of ways, including moderation tools that can be integrated into many blogging platforms and human review. The link attributes of “ugc” and “nofollow” will continue to be a further deterrent. In most cases, the move to a hint model won’t change the nature of how we treat such links. We’ll generally treat them as we did with nofollow before and not consider them for ranking purposes. We will still continue to carefully assess how to use links within Search, just as we always have and as we’ve had to do for situations where no attributions were provided.

When do these attributes and changes go into effect?
All the link attributes, sponsored, ugc and nofollow, now work today as hints for us to incorporate for ranking purposes. For crawling and indexing purposes, nofollow will become a hint as of March 1, 2020. Those depending on nofollow solely to block a page from being indexed (which was never recommended) should use one of the much more robust mechanisms listed on our Learn how to block URLs from Google help page.

Posted by Danny Sullivan and Gary