This abstract class defines a base interface for any user defined custom annotation mark. The user implements a custom mark class by deriving from this base class. Custom mark class resides in the user application, as well as custom mark controller and custom mark annotator controller.

The ImGearARTCustomMark class has a similar public API to what the existing marks have. The only custom mark’s specific property is UserType read-only property of type string. It is used to distinguish marks of different custom types. This property is used by ART to determine which registered type should be used when ART page is loaded. This property should be overridden in users custom mark class. Its value must be unique for each custom mark class implemented in user application.