XML messages

XML messages fall into the hierarchical division of message types. The XML DOM (Document Object Model) considers the elements of XML documents to fundamentally exist in parent/child tree relationships. The full W3C recommendation for XML includes new organizational concepts, including:

  • Conditionality, where an XML message element may exist in a relationship with another contender element for the same location in the message.
  • Infinite recursive constructs, where a message element can refer to itself.

XML also recognizes a fixed, sequential organization in which one message element must follow another message element within the message. It also generalizes the concepts of optionality and repeatability under the heading of cardinality.