| <result><section shorttitle="How does SGML work?"> | |
| <title>How is SGML and would you recommend it to your grandmother?</title> | |
| <intro> | |
| <para>You can break a typical document into three layers: structure, | |
| content, and style. SGML works by separating these three aspects and | |
| deals mainly with the relationship between structure and content.</para></intro> | |
| <topic topicid="top4"> | |
| <title>Structure</title> | |
| <para>At the heart of an SGML application is a file called the DTD, or | |
| Document Type Definition. The DTD sets up the structure of a document, | |
| much like a database schema describes the types of information it | |
| handles.</para> | |
| <para>A database schema also defines the relationships between the | |
| various types of data. Similarly, a DTD specifies <emph>rules</emph> | |
| to help ensure documents have a consistent, logical structure.</para></topic> | |
| <topic topicid="top5"> | |
| <title>Content</title> | |
| <para>Content is the information itself. The method for identifying | |
| the information and its meaning within this framework is called | |
| <emph>tagging</emph>. Tagging must | |
| conform to the rules established in the DTD (see <xref xrefid="top4"/>).</para> | |
| <graphic graphname="tagexamp"/></topic> | |
| <topic topicid="top6"> | |
| <title>Style</title> | |
| <para>SGML does not standardize style or other processing methods for | |
| information stored in SGML.</para></topic></section></result> |