|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
|Required sequence: Element1 followed by Element2 followed by Element3
|Choice of sequence: Element1 or Element2 or Element3
|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