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 |