Document Hierarchy Diagrams
Key to the Near & Far Diagrams
Element Occurrences
| Required |
| Optional. May occur zero or one times. |
| Required, repeatable. May occur one or more times. |
| Optional, repeatable. May occur zero or more times. |
Additional Symbols Associated with Elements
| Element content is expanded elsewhere in the diagram. |
| The element has attributes. |
| One or more elements collapsed for clarity |
| Element is the root element of the model. |
| Text, numbers, and special characters |
Grouping Elements
| Required sequence: Element1 followed by Element2 followed by Element3 |
| Choice of sequence: Element1 or Element2 or Element3 |
Compound Examples
| Zero or more repetitions of Element1 or Element2 or Element3 followed by zero or one occurrences of Element4 |
| Zero or one occurrences of either Element1 followed by Element2 followed by Element3 or one or more occurrences of Element4 |
| Either one or more repetitions of Element1 followed by Element2 or one or more occurrences of Element4 |