External data group properties - References tab
All existing references to other data groups are listed here.
Add reference
Opens a dialog where a new reference can be created.
Delete reference
Removes a reference from the list.
Edit reference
Opens a dialog where the currently selected reference can be edited.
The relationship to a reference data group is always defined using a foreign key whose value is compared in both data groups. In general, the values of the foreign key correspond to the primary key of the referenced data group.