Data within an MT940/950 messages is transformed and flattened to a row of data with the following fields in Duco.
| Duco field name | Duco field type | SWIFT Tag |
| DataType | Text | "Transactions" or "Balances" |
| Block1_AppID | Text | 1a |
| Block1_ServiceID | Text | 2n |
| Block1_LTAddress_IdCode | Text | 8c |
| Block1_LTAddress_LT | Text | 1c |
| Block1_LTAddress_Branch | Text | 3c |
| Block1_SessionNumber | Integer | 4n |
| Block1_SequenceNumber | Integer | 6n |
| Block2_Input/Output | Text | 1a |
| Block2_MessageType | Integer | 3n |
| Block2_DestinationAddress_IdCode | Text | 8c |
| Block2_DestinationAddress_LT | Text | 1c |
| Block2_DestinationAddress_Branch | Text | 3c |
| Block2_Priority | Text | 1a |
| Block2_DeliveryMonitoring | Integer | 1x |
| Block2_ObsolescencePeriod | Integer | 3n |
| Block2_InputTime | Integer | 4n |
| Block2_MIR | Text | 28c |
| Block2_OutputDate | Date | 6n |
| Block2_OutputTime | Time | 4n |
| Block3_ServiceIdentifier | Text | {103:3!a} |
| Block3_BankingPriority | Text | {113:4!x} |
| Block3_MUR | Text | {108:16!x} |
| Block3_ValidationFlag | Text | {119:8c} |
| Block3_BalanceCheckpoint_Date | Date | {423:YYMMDDHHMMSS[ss]} |
| Block3_BalanceCheckpoint_Time | Time | {423:YYMMDDHHMMSS[ss]} |
| Block3_BalanceCheckpoint_DecimalFractions | Integer | {423:YYMMDDHHMMSS[ss]} |
| Block3_MIR_Date | Date | {106:} 6n |
| Block3_MIR_LTIdentifier | Text | {106:} 4a2a2c1c |
| Block3_MIR_BranchCode | Text | {106:} 3c |
| Block3_MIR_SessionNumber | Integer | {106:} 4n |
| Block3_MIR_SequenceNumber | Integer | {106:} 6n |
| Block3_RelatedReference | Text | {424:16x} |
| Block3_ServiceTypeIdentifier | Text | {111:3!n} |
| Block3_UniqueEndToEndTransactionReference | Text | {121:xxxxxxxx-xxxx-4xxx-yxxxxxxxxxxxxxxx} |
| Block3_AddresseeInformation | Text | {115:32x} |
| Block3_PaymentRelease_ServiceTypeIdentifier | Text | {165:/3!c/34x} |
| Block3_PaymentRelease_UniqueEndToEndTransactionReference | Text | {165:/3!c/34x} |
| Block3_SanctionsSceening_Codeword | Text | {433:/3!a/[20x]} |
| Block3_SanctionsSceening_AdditionalInformation | Text | {433:/3!a/[20x]} |
| Block3_PaymentControls_Codeword | Text | {434:/3!a/[20x] |
| Block3_PaymentControls_AdditionalInformation | Text | {434:/3!a/[20x]} |
| Block4_TransactionReferenceNumber | Text | :20:16x (no characters limits) |
| Block4_RelatedReference | Text | :21:16x (no characters limits) |
| Block4_AccountId_Account | Text | :25P:35x OR :25:35x (no characters limits) |
| Block4_AccountId_IdCode | Text | 4!a2!a2!c[3!c] |
| Block4_StatementNumber | Integer | :28C:5n[/5n] |
| Block4_SequenceNumber | Integer | :28C:5n[/5n] |
| Block4_InitialOpeningBalance_DebitOrCreditMark | Text | :60F:1!a6!n3!a15d |
| Block4_InitialOpeningBalance_Date | Date | :60F:1!a6!n3!a15d |
| Block4_InitialOpeningBalance_Currency | Text | :60F:1!a6!n3!a15d |
| Block4_InitialOpeningBalance_Amount | Decimal | :60F:1!a6!n3!a15d |
| Block4_IntermediateOpeningBalance_DebitOrCreditMark | Text | :60M:1!a6!n3!a15d |
| Block4_IntermediateOpeningBalance_Date | Date | :60M:1!a6!n3!a15d |
| Block4_IntermediateOpeningBalance_Currency | Text | :60M:1!a6!n3!a15d |
| Block4_IntermediateOpeningBalance_Amount | Decimal | :60M:1!a6!n3!a15d |
| Block4_StatementLine_Date | Date | :61:6!n[4!n]2a[1!a]15d1!a3!c16x[//16x] [34x] |
| Block4_StatementLine_EntryDate | Integer | :61:6!n[4!n]2a[1!a]15d1!a3!c16x[//16x] [34x] |
| Block4_StatementLine_DebitOrCreditMark | Text | :61:6!n[4!n]2a[1!a]15d1!a3!c16x[//16x] [34x] |
| Block4_StatementLine_FundsCode | Text | :61:6!n[4!n]2a[1!a]15d1!a3!c16x[//16x] [34x] |
| Block4_StatementLine_Amount | Decimal | :61:6!n[4!n]2a[1!a]15d1!a3!c16x[//16x] [34x] |
| Block4_StatementLine_TransactionType | Text | :61:6!n[4!n]2a[1!a]15d1!a3!c16x[//16x] [34x] |
| Block4_StatementLine_IdCode | Text | :61:6!n[4!n]2a[1!a]15d1!a3!c16x[//16x] [34x] |
| Block4_StatementLine_ReferenceForTheAccountOwner | Text | :61:6!n[4!n]2a[1!a]15d1!a3!c16x[//16x] [34x] |
| Block4_StatementLine_AccountServicingReference | Text | :61:6!n[4!n]2a[1!a]15d1!a3!c16x[//16x] [34x] |
| Block4_StatementLine_SupplementaryDetails | Text | :61:6!n[4!n]2a[1!a]15d1!a3!c16x[//16x] [34x] |
| Block4_StatementLine_InformationToAccountOwner | Text | :86:6*65x (no characters limits) |
| Block4_FinalClosingBalance_DebitOrCreditMark | Text | :62F:1!a6!n3!a15d |
| Block4_FinalClosingBalance_Date | Date | :62F:1!a6!n3!a15d |
| Block4_FinalClosingBalance_Currency | Text | :62F:1!a6!n3!a15d |
| Block4_FinalClosingBalance_Amount | Decimal | :62F:1!a6!n3!a15d |
| Block4_IntermediateClosingBalance_DebitOrCreditMark | Text | :62M:1!a6!n3!a15d |
| Block4_IntermediateClosingBalance_Date | Date | :62M:1!a6!n3!a15d |
| Block4_IntermediateClosingBalance_Currency | Text | :62M:1!a6!n3!a15d |
| Block4_IntermediateClosingBalance_Amount | Decimal | :62M:1!a6!n3!a15d |
| Block4_ClosingAvailableBalance_DebitOrCreditMark | Text | :64:1!a6!n3!a15d |
| Block4_ClosingAvailableBalance_Date | Date | :64:1!a6!n3!a15d |
| Block4_ClosingAvailableBalance_Currency | Text | :64:1!a6!n3!a15d |
| Block4_ClosingAvailableBalance_Amount | Decimal | :64:1!a6!n3!a15d |
| Block4_ForwardAvailableBalance_DebitOrCreditMark | Text | :65:1!a6!n3!a15d |
| Block4_ForwardAvailableBalance_Date | Date | :65:1!a6!n3!a15d |
| Block4_ForwardAvailableBalance_Currency | Text | :65:1!a6!n3!a15d |
| Block4_ForwardAvailableBalance_Amount | Decimal | :65:1!a6!n3!a15d |
| Block4_InformationToAccountOwner | Text | :86:6*65x (no characters limits) |