Identifier at the source system for the population. Used during import to determine if the entity already exists in the target system (update) or is new (create). Must remain stable in the source system for the same entity. The name of the population Detailed description of the population The time period during which events occurred for this population. Absent start means the start date is historically unknown; absent end means the period is ongoing. The time period to which the population data refers. Absent start means the start date is historically unknown; absent end means the period is ongoing. Geographic scope or boundaries of the population Reference to Universe (instantiates universe)