Gary Illyes from Google, after multiple days of research, has confirmed that Google indeed supports the use of the nofollow link attribute on HTML link tags.
He said on Twitter this is supported in "the form of rel="alternate nofollow", and that will prevent Google from using the link from the href attribute. If you don't specify a nofollow, the URL from href will be extracted as a weightless outlink."
Gary added that Google has "many systems that can do URL extraction that may be used for discovery. For instance, Googlebot itself can do some minimal extraction, rendering can do advanced extraction, HTML parser can do extraction," he said this is why it took him several days to get an answer on this question.
Here are the tweets on this from Gary:
First, the answer: yes, you can use nofollow on
— Gary 鯨理／경리 Illyes (@methode) June 17, 2020
Third, the sitemaps processing system i still have to test (*), cos it does find the link tags, too, but for that particular system i suspect a robotstxt rule would be better.
— Gary 鯨理／경리 Illyes (@methode) June 17, 2020
* - it was written by someone who's been a c++ arbiter for years; i barely understand their code.
And yes, you can use the rel ugc and sponsored or both on these as well:
Since i can't decide if you were serious: nofollow and ugc are the same from every aspect except that ugc carries a bit of info in its name about WHY you decided to annotate the href. Using both, from Google's perspective, is useless.
— Gary 鯨理／경리 Illyes (@methode) June 17, 2020
This all came about because Joost from Yoast wants to tell Google not to crawl the comment RSS feeds of WordPress sites.
So this started because of Google crawling the comment RSS feeds of WordPress sites. Those are kinda useless, but exist for every single post.
— Joost de Valk (@jdevalk) June 18, 2020
So, even it’s a hint they follow 50% of the time, if we nofollow all of them, we prevent loads and loads of useless crawling.
So this might help him and his team come up with a mechanism to communicate to Google, not to follow links to these comment RSS feeds.
Nah, link tags' hrefs are useless for ranking
(as in HTML June 18, 2020
Forum discussion at Twitter.
Update: Bing said it depends:
Our parser extracts that. After, that’s ML based and the ML stack is learning and adjusting everyday. Today ML stack may use that globally or partially (e.g. set of sites, CMS) and next month the ML stack may think differently. Not as easy as a simple statement (IF nofollow then)
— Fabrice Canel (@facan) June 18, 2020
