The diagram below represents the top-level structural subdivision of the ONIX DTD. It shows that an ONIX message element (represented by the box on the extreme left) is made up of either a sequence of header data elements (which must include identification of the sender and the date on which the message was sent) or the same sequence of data elements enclosed within a composite element Header, followed by at least one Product, Main Series or Subseries record.

The diagrams displayed on these pages have been created using XML Authority™, a DTD and Schema editing and visualizing tool from TIBCO SoftwareInc.