• Chapter 1: Getting Started with Stylus Studio®
• Chapter 2: Editing and Querying XML
• Chapter 3: Converting Non-XML Files to XML
• Chapter 4: Working with XSLT
• Chapter 5: Creating XSLT Using the XSLT Mapper
• Chapter 6: Debugging Stylesheets
• Chapter 7: Defining XML Schemas
• Chapter 8: Defining Document Type Definitions
  • What Is a DTD?
  • Creating DTDs
  • About Editing DTDs
  • About Modifiers in Element Definitions in DTDs
    • Description of Element Modifiers in DTDs
    • Simple Example of Aggregating Modifiers in DTDs
    • More Complex Example of Aggregating Modifiers in DTDs
    • Aggregating Modifiers to Allow Any Order and Any Number in DTDs
  • Defining Elements in DTDs
  • Defining General Entities and Parameter Entities in DTDs
  • Inserting White Space in DTDs
  • Adding Comments to DTDs
  • About Node Properties in DTDs
  • Associating an XML Document with an External DTD
  • Moving an Internal DTD to an External File
• Chapter 9: Writing XPath Expressions
• Chapter 10: Working with XQuery in Stylus Studio
• Chapter 11: Composing Web Service Calls
• Chapter 12: Accessing Relational Data as XML
• Chapter 13: Building XML Pipelines
• Chapter 14: Publishing XML Data
• Chapter 15: Integrating with Third-Party File Systems
• Chapter 16: Extending Stylus Studio
• Chapter 17: The Stylus Studio Java API
• Chapter 18: Stylus Studio GUI Reference

Home > Online Product Documentation > Table of Contents > Aggregating Modifiers to Allow Any Order and Any Number in DTDs

Aggregating Modifiers to Allow Any Order and Any Number in DTDs

The Choice modifier specifies that only one of the specified elements can appear in an instance document. However, if you specify the Zero or More modifier and then the Choice modifier, the result is that the specified elements can appear in any order and each element can appear any number of times.

The text for such an element definition is as follows:

<!ELEMENT A (B|C|D)*>
               

            

The tree representation is as follows:

A
               

              

                
Zero or More
                   
Choice
                   
	B
                   
	C
                   
	D
                   

                
              

            

This allows an A element to contain

Furthermore, the contained elements can be in any order.