Create a new special field type called Canonical URL for use in a Blogs Post Collection for syndicated blog posts (posts whose original/master copies are elsewhere). By setting a valid URL in this field this would make it possible to show where blog articles using a syndicated article so we can point back to the canonical original article on the author's blog using a canonical link (maintaining SEO).
Filling in this field would automatically create this under the hood: A canonical link in HTML
<head> section ONLY for syndicated blog posts.
To do this a rel="canonical" link needs to be added into the head area of a blog posts template creating this:
<link rel="canonical" href="www.someblog.com/someblogpost">
in the head section - note. it should not add anything if the href is blank (or an invalid URL/broken link).
Justification and why hand-coding is not the answer
Attempting to hand code this in the Custom Code - Inside <head> tag section is very complicated and does not seem to work despite a large number of forum post suggestions as to how this might be achieved. This will be a requirement for anybody that has blog posts that include at least one syndicated post - not least as this is vital for SEO so syndication doesn't look like duplication and therefore you find your lovely webflow site is punished by search engine companies and not appearing in search results.