<!-- DTD for a hypothetical mediamanagement system --><!-- Media assets are the root of the object hierarchy. Assets are alsohierarchical - they can contain other assets. --><!ELEMENT media-asset(name, desc?, type*, media-asset*, urn)><!-- Metadata about the asset --><!ELEMENT name (#PCDATA)><!ELEMENT desc (#PCDATA)><!ELEMENT type (desc, mime-type?)><!ELEMENT mime-type (#PCDATA)><!ELEMENT urn (#PCDATA)>

<?xml version="1.0" ?><!DOCTYPE media-asset PUBLIC "-//Jim Farley//DTD Media Assets//EN" "http://localhost/Articles/Sun/dtds/media.dtd"><media-asset><name>第14講</name><desc>與第14講相關的所有內容</desc><!-- 內容對象"lecture 14"的一套子組件 --> <media-asset><name>講座的幻燈片</name><type><desc>MS Powerpoint</desc><mime-type>application/vnd.ms-powerpoint</mime-type></type><urn>http://javatraining.org/jaf/E123/lecture-14/slides.PPT</urn></media-asset><media-asset><name>講座的視頻片斷</name><type><desc>RealPlayer streaming video</desc><mime-type>video/vnd.rn-realvideo</mime-type></type><urn>http://javatraining.org/jaf/E123/lecture-14/lecture.rv</urn></media-asset><!-- 講座開始 --><urn>http://javatraining.org/jaf/E123/lecture-14/index.jsp</urn></media-asset>