Business owners trying to promote a brand online often need to post duplicates of the same articles across the Internet. For example, the business may want to produce an informational article on an online publishing outlet like Medium in order to illustrate to potential customers that the brand offers valuable insight into its respective industry. For viewers browsing the Internet who become aware of the business under different circumstances, however, the business' owner would do well to have a copy of that article posted within its own domain so that those visitors can receive the same valuable insight. However, this effort toward serving audiences across multiple online platforms can ironically undermine the website's efforts to actually attain high rankings in SERPs on Google and the like. Duplicating content without the right syntax results in Google refusing to award higher rankings to any websites that receive the same piece of content as a site that has already been indexed. If a business' owner posts their article on Medium before posting it on their own website, Google will unfairly consider that website to be hosting "duplicate content" and make the Medium version of the article the version that is displayed at the forefront of SERPs. Google can be instructed to consider a particular version of an article the "canonical" incarnation of it so that the website hosting that version receives its due ranking credit as the originator of that piece of content. The official method of designating a web page as such requires a fair amount of planning in advance, however. Whoever is posting the duplicates of the content needs to insert a link tag in each of those those duplicates' header sections that points to the original website and includes an element indicating that the linked version is canonical in comparison to the current version. If the owner forgets to include this element in a copy of an article posted on an outlet like Medium where uploaders may not be allowed to edit submitted posts, the outlet's staff will have to be asked to put it in on the uploader's behalf. For more information click here https://www.reddit.com/r/SEO/comments/a2b9dn/ivemessedupinrelcanonicalbypostingin/.