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 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."...
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Google Does Support Nofollow On HTML Link Tag
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