The question was about the proper use of “blockquote tags”, but it was also about what the search engine considers “duplicate content”.
Here are the articles that explain everything clearly. Good to know!
The HTML Tags that Deal with Text (HTML Tutorial Chapter 2)
https://www.thesitewizard.com/html-tutorial/html-4-xhtml-tutorial-2.shtml
4 Things to Be Aware of When Writing English Content for an International Audience
https://www.thesitewizard.com/general/beware-of-english-variants.shtml
Google Support : Duplicate content
https://support.google.com/webmasters/answer/66359?hl=en
What is Duplicate Content?
https://moz.com/learn/seo/duplicate-content







