Example of a DTD document.

DTD_Sample.dtd

<?xml version="1.0" encoding="UTF-8"?>
<!-- Bookstore with DTD                    -->
<!-- Try changes:                          -->
<!--   Make Edition required               -->
<!--   Swap order of First_Name, Last_Name -->
<!--   Add empty Remark                    -->
<!--   Add Magazine, omit closing tag      -->
<!DOCTYPE Bookstore [
   <!ELEMENT Bookstore (Book | Magazine)*>
   <!ELEMENT Book (Title, Authors, Remark?)>
   <!ATTLIST Book ISBN CDATA #REQUIRED
                  Price CDATA #REQUIRED
                  Edition CDATA #IMPLIED>
   <!ELEMENT Magazine (Title)>
   <!ATTLIST Magazine Month CDATA #REQUIRED Year CDATA #REQUIRED>
   <!ELEMENT Title (#PCDATA)>
   <!ELEMENT Authors (Author+)>
   <!ELEMENT Remark (#PCDATA)>
   <!ELEMENT Author (First_Name, Last_Name)>
   <!ELEMENT First_Name (#PCDATA)>
   <!ELEMENT Last_Name (#PCDATA)>
]>
<Bookstore>
   <Book ISBN="ISBN-0-13-713526-2" Price="85" Edition="3rd">
      <Title>A First Course in Database Systems</Title>
      <Authors>
         <Author>
            <First_Name>Jeffrey</First_Name>
            <Last_Name>Ullman</Last_Name>
         </Author>
         <Author>
            <First_Name>Jennifer</First_Name>
            <Last_Name>Widom</Last_Name>
         </Author>
      </Authors>
   </Book>
   <Book ISBN="ISBN-0-13-815504-6" Price="100">
      <Title>Database Systems: The Complete Book</Title>
      <Authors>
         <Author>
            <First_Name>Hector</First_Name>
            <Last_Name>Garcia-Molina</Last_Name>
         </Author>
         <Author>
            <First_Name>Jeffrey</First_Name>
            <Last_Name>Ullman</Last_Name>
         </Author>
         <Author>
            <First_Name>Jennifer</First_Name>
            <Last_Name>Widom</Last_Name>
         </Author>
      </Authors>
      <Remark>
         Buy this book bundled with "A First Course" - a great deal!
      </Remark>
   </Book>
</Bookstore>