DTD 教程,DTD

DTD 教程DTD（文档类型定义）的作用是定义 XML 文档的合法构建模块。DTD 可被成行地声明于 XML 文档中，也可作为一个外部引用。现在开始学习DTD!DTD 新闻实例<!DOCTYPE NEWSPAPER [<!ELEMENT NEWSPAPER (ARTICLE+)><!ELEMENT ARTICLE (HEADLINE,BYLINE,LEAD,BODY,NOTES)><!ELEMENT HEADLINE (#PCDATA)><!ELEMENT BYLINE (#PCDATA)><!ELEMENT LEAD (#PCDATA)><!ELEMENT BODY (#PCDATA)><!ELEMENT NOTES (#PCDATA)>?<!ATTLIST ARTICLE AUTHOR CDATA #REQUIRED><!ATTLIST ARTICLE EDITOR CDATA #IMPLIED><!ATTLIST ARTICLE DATE CDATA #IMPLIED><!ATTLIST ARTICLE EDITION CDATA #IMPLIED>]>