slide 35

DTDs / Schemas Express Rules

for example:

• Reference book =
  Book-level Metadata followed by
  Front Matter followed by
  Body followed by
  Back Matter (which is optional)
• Purchase Order =
  Order Header followed by
  List of Order Detail followed by
  Order Summary (which is optional)
• paragraph =
  data characters and may include any of the following: Person Names, URLs, and/or Geographic Regions