Curly Quotes on the World-Wide Web

If you want to use more attractive curly quotes in documents
published on the WWW, it is recommended to use decimal numeric
character references instead of HTML character entities in order to
make text shareable between HTML, XML, and SGML documents.

  Quotation mark         Numeric ref.     HTML entity

  Left double quote      “          “
  Right double quote     ”          ”
  Left single quote      ‘          ‘
  Right single quote     ’          ’

Source: David A. Wheeler. Curling Quotes in HTML, SGML, and
        XML. <https://www.dwheeler.com/essays/quotes-in-html.html>
        accessed 8 Sep. 2018.