This field is used when imports/exports are carried out under the XML format.
Indeed, when a XML file is created, some more information are required, especially in order to create a XSD file describing the structure of the XML file and then, to control its validity with syntax check tools integrated to the different ETL software.
This field defines whether the field is mandatory or not. If the value of this field is set to Yes, the XSL file will contain a specification of minOccurs="1" type