Three structures contain the data that travels with an item while it is being dragged; these are the DRAGINFO, DRAGITEM and DRAGIMAGE structures. A further structure, the DRAGTRANSFER structure, is used to transfer information between source and target windows after a drop has occurred.
Details of the fields within these structures can be found in the IBM OS/2 Version 2.0 Presentation Manager Reference, and full descriptions will not be given here. However, the following sections describe in general terms the kind of data the structures contain, and particularly certain critical fields.