The COMM_CO_EXTENSION_2 element MUST contain a CHANGE_ORDER_RECORD_EXTENSION structure, which is an extension to the CHANGE_ORDER_COMMAND structure. The structure of the COMM_CO_EXTENSION_2 packet element is as follows.

 typedef struct _COMM_CO_EXTENSION_2 {
   USHORT CommType;
   ULONG Length;
   CHANGE_ORDER_RECORD_EXTENSION Data;
 } COMM_CO_EXTENSION_2,
  *PCOMM_CO_EXTENSION_2;

CommType: A 16-bit, unsigned integer that indicates the type of this COMM_PACKET element. MUST set to 0x0017.

Length: A 32-bit, unsigned integer that indicates the length in bytes of the data following the Length field. MUST be set to the FieldSize member of the CHANGE_ORDER_RECORD_EXTENSION structure, which is 0x00000048 (72 bytes).

Data: The data that is being transmitted in the form of a CHANGE_ORDER_RECORD_EXTENSION (see section 2.2.3.4).