<P> The third digit (3) is the type that denotes the specific message . There are several hundred message types across the categories . The type represented by 3 is a notification . </P> <P> Below are the fields of an MT 103 message . These fields are referred to as tags . </P> <Table> <Tr> <Td> Field </Td> <Td> Field Name </Td> </Tr> <Tr> <Td>: 20 </Td> <Td> Transaction Reference Number </Td> </Tr> <Tr> <Td>: 23B </Td> <Td> Bank Operation Code </Td> </Tr> <Tr> <Td>: 32A </Td> <Td> Value Date / Currency / Interbank Settled </Td> </Tr> <Tr> <Td>: 33B </Td> <Td> Currency / Original Ordered Amount </Td> </Tr> <Tr> <Td>: 50A, F or K </Td> <Td> Ordering Customer (Payer) </Td> </Tr> <Tr> <Td>: 52A or D </Td> <Td> Ordering Institution (Payer's Bank) </Td> </Tr> <Tr> <Td>: 53A, B or D </Td> <Td> Sender's Correspondent (Bank) </Td> </Tr> <Tr> <Td>: 54A, B or D </Td> <Td> Receiver's Correspondent (Bank) </Td> </Tr> <Tr> <Td>: 56A, C or D </Td> <Td> Intermediary (Bank) </Td> </Tr> <Tr> <Td>: 57A, B, C or D </Td> <Td> Account with Institution (Beneficiary's Bank) </Td> </Tr> <Tr> <Td>: 59 or 59A </Td> <Td> Beneficiary </Td> </Tr> <Tr> <Td>: 70 </Td> <Td> Remittance Information </Td> </Tr> <Tr> <Td>: 71A </Td> <Td> Details of Charges (OUR / SHA / BEN) </Td> </Tr> <Tr> <Td>: 72 </Td> <Td> Sender to Receiver Information </Td> </Tr> <Tr> <Td>: 77A </Td> <Td> Regulatory Reporting </Td> </Tr> </Table> <Tr> <Td> Field </Td> <Td> Field Name </Td> </Tr>

What is field 20 in a swift message