The class associated with the type. This class is the active portion of the type and resides in the specified library. If this class is not in the default library namespace specified on the root AddIn element, the class name must be the full name (namespace.className).

Namespace: http://schemas.esri.com/Desktop/AddInsSchema: DesktopAddIns_ElementOnly.xsd

<xs:attribute name="class" type="xs:string" use="required" xmlns:xs="http://www.w3.org/2001/XMLSchema"></xs:attribute>