Handle returned upon registration.

typedef struct _VRAMREGISTEROUT {
  ULONG     ulLength;  /*  Length of VRAMREGISTEROUT data structure, in bytes.  */
  ULONG     ulFlags;   /*  Not used at this time. */
  ULONG     ulHandle;  /*  Unique ID. */
} VRAMREGISTEROUT;

typedef   VRAMREGISTEROUT   * PVRAMREGISTEROUT ;