If you create a code list in a dependent reference data set, the code list inherits the parent dependency from the dependent reference data set. If you create a code list in a reference data set without a dependent structure definition, you can define the code list as dependent. After you create a dependent code list, you cannot change the dependency.

For more information about actions that are allowed after code list creation, see Code lists.

For example, you have a Country Codes reference data set. When you create a State Codes reference data set, you define the structure definition as dependent and configure the Country Codes reference data set as the parent dependency. Then when you create code lists in the State Codes reference data set, the code lists inherit the dependency on the Country Codes reference data set. For each code list in the State Codes reference data set, you can choose the code list dependency. A code list dependency defines the dependent relationship between one code list and another. You might want the Enterprise State Codes code list to depend on the Enterprise Country Codes code list.