ArcGIS Pro 3.0 API Reference Guide
ArcGIS.Desktop.Mapping Namespace / PopupDefinition Class / Append Property

Append Property
Gets or sets whether content already in the dockable window is kept or cleared. Only used when dockable is true.
Syntax
public bool Append {get; set;}
Requirements

Target Platforms: Windows 11, Windows 10, Windows 8.1

ArcGIS Pro version: 2.5 or higher.
See Also