2 Structures

 In the following sections, the schema definition might be less restrictive than the processing rules imposed by the application. The XSD in this specification provides a base description of the file format. The text that introduces the XSD specifies additional restrictions that reflect actual Microsoft product behavior. For example, the schema definition might allow for an element to be empty, null, or not present but the behavior of the application as specified restricts the same elements to being non-empty, not null, and present.