University of Cincinnati logo and link  
Document Type Definitions
 
  UC ingot The parser can automatically verify the structure of an XML document if we provide that information to the file.  We provide that in a DTD, or Document Type Definitions file.
    • You can provide the DTD inside the XML file itself.
    • But a better approach is to have a separate DTD file and link it to the XML file. 
      • Remember this line? 
      <!DOCTYPE web-app 
          PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" 
          "http://java.sun.com/dtd/web-app_2_3.dtd"> 
      That's the line that links the DTD file to our XML file.  It can either be a local file or a URL.
 DTD ELEMENT Rules