This class method enumerates through all the object classes that a particular rendering mechanism supports.

#define INCL_WINWORKPLACE
#include <os2.h>

M_WPDataFile     *somSelf;    /*  Pointer to the WPDataFile class object. */
ULONG             aCBFormat;  /*  Atom referring to the clipboard format. */
ULONG             aPrevious;  /*  The last atom passed in or 0 to start from the beggining. */
ULONG             rv;         /*  An atom referring to a class name, or 0 if finished. */

rv = _wpclsEnumClipboardClasses(somSelf, aCBFormat,
       aPrevious);