By default, Drill Down Graph PRO uses the node IDs as node display names (as defined by the Source Nodes and Target Nodes fields). Node IDs in these fields cannot contain spaces, which may impact readability or appearance of the chart.

You can use this field to assign a custom display name for the source node independently from its node ID. For example, if the source node ID is “UnitedStates", entering the full name with spaces in this field (“United States of America”) will display it properly.