The TRANSFER_TYPE enumeration specifies the valid cases for the unnamed union defined in the CACTransferBufferV1 structure (section 2.2.3.2).

 typedef  enum {
   CACTB_SEND = 0,
   CACTB_RECEIVE,
   CACTB_CREATECURSOR
 } TRANSFER_TYPE;

CACTB_SEND:  A send operation (that is, a message placed into a queue for delivery) is to be performed.

CACTB_RECEIVE:  A receive operation (that is, a message is to be read from a queue) is to be performed.

CACTB_CREATECURSOR:  A cursor creation is to be performed.