Bing supports rel=sponsored & rel=ugc
You can use the rel="nofollow" or rel="sponsored" or rel="ugc" attributes, to "prevent the links from being followed by a crawler and from potentially impacting search rankings.
A new tidbit found in the updated Bing Webmaster Guidelines is that Bing now supports rel=”sponsored” and rel=”ugc” attributes on your links. This is in addition to Bing supporting the rel=”nofollow” link attribute, which we know it has supported since its introduction over ten years ago.
New link attributes. These two new link attributes were introduced by Google last September. These are how these attributes are handled. Bing wrote in the guidelines “make a reasonable effort to ensure that any paid or advertisement links on your site use rel=”nofollow” or rel=”sponsored” or rel=”ugc” attribute to prevent the links from being followed by a crawler and from potentially impacting search rankings.”
rel="sponsored": The new sponsored attribute can be used to identify links on your site that were created as part of advertisements, sponsorships or other compensation agreements.
ugc attribute value is recommended for links within user generated content, such as comments and forum posts.
A Bing spokesperson confirmed with Search Engine Land that these link attributes are treated as hints, not necessarily directives. So technically Bing can decide to still follow these links if it deemed necessary. The rel sponsored and rel ugc attributes are being monitored by Bing and are “not as strong of a signal for Bing,” we were told. This may change based on adoption rates over time.
Why we care. This means that if you do decide to add these attributes to your site, Bing will also take these into account. Bing’s guidelines says you can use all three, the rel=”nofollow” or rel=”sponsored” or rel=”ugc” attributes, to “prevent the links from being followed by a crawler and from potentially impacting search rankings.”