Certain special characters are represented in HTML by a name or a number, referred to as an entity . HTML includes entity names for characters such as the copyright symbol (©), the ampersand (&), and the registered-trademark symbol (®). Each entity has both a name (such as —) and a numeric equivalent (such as —).
Unfortunately, many browsers (especially older browsers, and browsers other than Netscape Navigator and Internet Explorer) don’t properly display many of the named entities.