The ActiveX Controls Architecture defines a data-binding mechanism, whereby an ActiveX Control can specify that one or more of its properties are bindable. In most cases, a data-bound control should not absolutely require data binding, so that it could be inserted into a container that does not support data binding. Obviously, in such a situation, the functionality of the control may be reduced.
CATID - {157083E1-2368-11cf-87B9-00AA006C8166} CATID_PropertyNotifyControl