Making elements optional or mandatory
By using dynamic behavior properties you can determine whether to show or hide specific fields.
If required, you can make fields optional or mandatory.
Optional / Mandatory
By including the function optional or mandatory, you ensure that the element becomes optional/mandatory on the form.
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Please note that optional or mandatory functions:
•    can only be applied to the questionnaire's Question fields;
•    can only be applied to simple field types such as String, Integer, Boolean, Big decimal etc.;
•    cannot be applied to Reference fields and File upload fields, due to technical limitations.
Example:
Dynamic behavior tabDynamic behavior tab
In the last row, it says that if you click any of the listed items except Other, an optional Comment field will be shown (QQ00000044):
Optional Comment fieldOptional Comment field
However, if the user would click Other, a mandatory Comment field will be shown:
Mandatory Comment fieldMandatory Comment field