Element Occurrences | ||
Required | ||
Optional. May occur zero or one time. | ||
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 | ||
Excluded elements that are prohibited from being within the current element |
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 occurrence 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 |