/*这个一个DTD文件,文件的开头你没写出来 所以我不知道根元素是什么。我估计是address
address 前面的是命名空间
addresses:address (addresses:buildingnumber, addresses:street,
addresses:city, addresses:state, addresses:zip)
表示addresses:address 下 有这些addresses:buildingnumber, addresses:street,
addresses:city, addresses:state, addresses:zip 子元素…*/
<!ELEMENT addresses:address (addresses:buildingnumber, addresses:street,
addresses:city, addresses:state, addresses:zip)>
<!ATTLIST addresses:address xmlns:addresses CDATA #IMPLIED> /*这是属性的定义*/
/*这后面是对各个具体的子元素的定义 #PCDATA表示数据类型*/
<!ELEMENT addresses:buildingnumber (#PCDATA)>
<!ELEMENT addresses:street (#PCDATA)>
<!ELEMENT addresses:city (#PCDATA)>
<!ELEMENT addresses:state (#PCDATA)>
<!ELEMENT addresses:zip (#PCDATA)>
/*写不大来注释 不晓得你看的懂不*/