A conceptual domain may be associated with either a data element concept or a value domain. A conceptual domain is not a mandatory association, and there may be a one-to-many relationship between a data element concept and a conceptual domain, or a value domain and a conceptual domain.
Countries of the world can be expressed as a conceptual domain. The concept of countries can be measured by both enumerated and non-enumerated value domains. An enumerated value domain may reference the Australian Standard Classification of Countries (2011) and provide a four digit code (i.e. NNNN). A non-enumerated value domain may still reference the same classification, but collect country names using a textual field instead (i.e Text X[X(99)]. Both the enumerated and non-enumerated value domains could be associated with the conceptual domain for countries. The conceptual domain might also be associated with several data element concepts which incorporate country as a central theme, such as Person —country of birth, Person — country of residence, or Person — country of citizenship.