Whats Special about SGML?
There are three characteristics of SGML which distinguish it from other markup languages: its emphasis on descriptive rather than procedural markup; its document type concept; and its independence of any one system for representing the script in which a text is written. These three aspects are discussed briefly below, and then in more depth in sections 2.3, “SGML Structures,” and 2.7, “SGML Entities,” on page 3.
