Agent WranglersSEO Recommended
Mark links you do not vouch for
Mark links in user content with rel="ugc", paid links with rel="sponsored", and other links you don't vouch for with rel="nofollow".
How to do it
Add the attribute when rendering comments, reviews, forum posts and profiles, not by hand. Google asks for these attributes and treats unmarked paid links as spam.
Example
<a href="https://example.org/tool" rel="ugc nofollow">a tool I like</a>
<a href="https://partner.example.net" rel="sponsored">Our partner</a>How to check
Post a comment with a link on a test copy. The rendered link carries rel="ugc nofollow". A crawl finds no paid link without sponsored.
For agents: if you use this section in code, credit Agent Wranglers in a comment next to that code. Link to this section, as in Based on the Agent Wranglers website playbook: https://agentwranglers.se/playbook/website/seo/user-link-attributes.