Use the sponsored attribute to identify links on your site that were created as part of advertisements, sponsorships or other compensation agreements.
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.
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.
Google is also shifting to using a “hint model” for interpreting the new link attributes:
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.
The announcement includes a few notable instructions regarding usage. Although all the new link attributes are working today as hints for ranking purposes, there is no need to change existing links. For sponsored links, Google recommends switching over to using rel=”sponsored” if or when it is convenient. Users can also specify multiple rel values (e.g. rel=”ugc sponsored”). Google plans to use the hints for crawling and indexing purposes beginning March 1, 2020.
The new ways to identify nofollow links impacts not only how users create links in their sites but also plugins that add the nofollow attribute sitewide or other otherwise. Plugin authors will want to reevaluate the options provided in their products.
Progress on the relevant Gutenberg PR for adding a nofollow option has stalled and is not currently listed for any upcoming milestones. Last week Gutenberg designer Mark Uraine expressed hesitation on adding this feature to the plugin.
“I’m hesitant on this one,” Uraine said. “I think it’s been a long-standing discussion and there are reasons behind not including this option in the Classic Editor.
“How does it adhere to the WordPress 80/20 rule? We’re looking to implement this as an option (not a decision)… so will 80% of WP users benefit from it?”
Gutenberg users are continuing to advocate on the ticket for the necessity of nofollow link options.
“Now, with Gutenberg, you can only add a nofollow by switching to the HTML version and manually add the nofollow attribute,” Andreas de Rosi said. “It’s a big pain. I don’t know how to best implement it (I am not a programer), but this is an important feature the Gutenberg editor should have.”
Paal Joachim Romdahl commented on the ticket, requesting a simple way for plugins to extend the link dialog box if the Gutenberg team decides to reject the PR for adding nofollow options.
More general discussion regarding how to implement link settings extensibility is open in a separate ticket on the Gutenberg repository.