This structure identifies a stream protocol.
typedef struct _SPCBKEY {
  ULONG     ulDataType;     /*  Data type for streaming operation. */
  ULONG     ulDataSubType;  /*  Data subtype. */
  ULONG     ulIntKey;       /*  Internal key. */
} SPCBKEY;
typedef   SPCBKEY   FAR   * PSPCBKEY ;