XML Information

• Welformed Xml documents must have the following properties.


• All XML elements must have a closing tag (except empty elements).
• All XML elements must be properly nested.
• All XML documents must have a root tag.
• Attribute values must always be quoted.


• Valid Xml document


• A "Valid" XML document is a "Well Formed" XML document which conforms to the rules of a Document Type Definition (DTD).


• Attributes vs Elements


• Attributes can not contain multiple values (elements can).
• Attributes are not expandable (for future changes).
• Attributes can not describe structures (like child elements can).
• Attributes are more difficult to manipulate by program code.
• Attribute values are not easy to test against a DTD.
• Use elements to describe your data.
• Use attributes only to provide information that is not relevant to the reader.

• Mother of all XML sites
• XML101 (good place for tutorials)
• Web Developers Virtual Libray (good pacle for tutorials)