ArcGIS Pro 2.6 API Reference Guide
UseDefaultSymbol Property (UniqueValueRendererDefinition)

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

Target Platforms: Windows 10, Windows 8.1, Windows 7

See Also

Reference

UniqueValueRendererDefinition Class
UniqueValueRendererDefinition Members