There are some characteristics that distinguish SGML from other markup languages. They are
- Descriptive Markup : The tags are descriptive such that they will be understood as soon as they are seen by anyone.
Example To mark up a letter the tag can be given the name <letter>
To mark up a paragraph the tag can be given the name<paragraph>
The information about this tags is collected outside the document in separate programs.
- Type of Document: SGML introduces the notion of a document type defination.
- Document Type Definition describes a model of the structure of the content of SGML Document. Each SGML document has its own DTD..
The document type Declration looks like <! DOCTYPE DTD.name[internal.subset] >
