After initializing a DDF buffer with DdfInitialize, the example uses DdfInform to create a hypertext inform link with another resource (corresponds to the IPF :link. tag with reftype=inform). For a more detailed example and discussion of initializing DDF, see the DdfInitialize sample.

#define INCL_WINWINDOWMGR       /* General window management    */
#define INCL_WINMESSAGEMGR      /* Message management           */
#define INCL_DDF                /* Dynamic Data Facility        */
#include <os2.h>
#include <pmhelp.h>

PSZ    Text = "This text is a HYPERTEXT message.\n"; /* hypertext string  */
MRESULT WindowProc( HWND hwnd, ULONG ulMsg, MPARAM mp1, MPARAM mp2 )
{
    HWND   hwndParent;
    HWND   hwndInstance;
    HDDF   hDdf;            /* DDF handle                           */

    switch( ulMsg )
    {
        case HM_QUERY_DDF_DATA:
            /* get the help instance */
            hwndParent = WinQueryWindow( hwnd, QW_PARENT );
            hwndParent = WinQueryWindow( hwndParent, QW_PARENT );
            hwndInstance = (HWND)WinSendMsg( hwndParent, HM_QUERY,
                                     MPFROMSHORT( HMQW_INSTANCE ), NULL );

        /* Allocate 1K Buffer (default)  */
        hDdf = DdfInitialize(
                        hwndInstance,  /* Handle of help instance */
                        0L,            /* Default buffer size     */
                        0L             /* Default increment       */
                        );

        if (hDdf == NULLHANDLE)       /* Check return code       */
        {
            return (MRESULT)FALSE;
        }

        /* create hypertext inform link with resource 1 */
        if (!DdfInform(hDdf, (PSZ)Text, 1L))
        {
            return (MRESULT)FALSE;
        }

        return (MRESULT)hDdf;
    }
}