For paperwork like PDFs, there’s no way to position canonical tags within the web page header for the reason that there isn't a web site section. In these instances, you’ll have to use HTTP headers to established canonicals. When you’re syndicating or republishing written content on other internet sites, this https://addons.prestashop.com/ru/seo-natural-search-engine-optimization/31857--rich-snippets-json-ld-opengraph-seo.html