GoObject.CanView() be true, but GetSelectionId must also return a unique ID for it. That ID, prefixed with "I", becomes the id of the generated element in the DOM. Any selection handles are also generated as a group; its id is the same, but prefixed with "H". This property affects the behavior of GenerateSelectionHandles, since when this property is false, there is no need to produce selection handle objects, other than those that are visible anyway if PaintView is true.