ArcGIS Pro 2.6 API Reference Guide
DefaultSymbol Property (UniqueValueRendererDefinition)

ArcGIS.Desktop.Mapping Namespace > UniqueValueRendererDefinition Class : DefaultSymbol Property
Gets or sets a symbol that will be used to draw features whose values are not found in values list.
Syntax
public CIMSymbolReference DefaultSymbol {get; set;}
Public Property DefaultSymbol As CIMSymbolReference
Remarks
You should use this when there are more unique values that what you set as ValuesLimit.
Note, this is only applicable when UseDefaultSymbol is set to true.
Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 7

See Also

Reference

UniqueValueRendererDefinition Class
UniqueValueRendererDefinition Members