QtDesigner, hide custom widget from designer toolbox. How?

Hi!

I create my custom widget, but I want HIDE it from designer toobox group. Is it possible?
class BmsCCatalogueSelectWidgetPlugin : public QObject, public QDesignerCustomWidgetInterface
{
Q_OBJECT
Q_INTERFACES(QDesignerCustomWidgetInterface)

public:
BmsCCatalogueSelectWidgetPlugin(QObject *parent = 0);

bool isContainer() const;
bool isInitialized() const;
QIcon icon() const;
QString domXml() const;
QString group() const;
QString includeFile() const;
QString name() const;
QString toolTip() const;
QString whatsThis() const;
QWidget *createWidget(QWidget *parent);
void initialize(QDesignerFormEditorInterface *core);

private:
bool initialized;
};