Document structure

The document hierarchy describes the structure of the documents that your application is designed to process. The levels within the hierarchy are batch, document, page, and field.

Diagram of the document hierarchy.
At the top of the document hierarchy is the batch, which refers to all pages of all document types. Beneath the batch level, the document hierarchy defines:
The document types your application can process
An application can process only one document type, or multiple document types. For example, the TravelDocs sample application can process car rental documents, hotel expense documents, and flight documents.
The page types within each document type
Each document can contain only one page type or multiple page types. For example, the TravelDocs car rental document includes the rental agreement page and the optional insurance page, while the flight document has only an air ticket page.
The number and order of pages within each document type
Pages can be required or optional. For example, a car rental document has two pages at most. The rental agreement page is required and must come first; and the insurance coverage page is optional.
The data fields within each page type
Data fields can be required or optional. For example, the hotel document's Other Charges page has fields for expense category, number of items, unit cost, and total cost. Nested fields are used for special purposes and creation of custom nested fields is not supported.