The parent-child relationship means that a local dataset inherits all flows from the parent unless otherwise specified – ensuring consistency of datasets for the same activity in different regions. It should therefore be used for groups of closely related datasets where the local datasets only differ by the amounts of the exchanges or parameter values.
This will also save you time as you only have to establish your system once and then you can adjust all necessary comments and values in the children datasets. Data which remain the same in the parent and in the children datasets can be changed in the parent only and all children will inherit the change.
Only geographical children can be created. The parent of a geography child is always the global dataset.
For more detailed information see the Data Quality Guidelines.