All Inbound messages are validated against the Message structure defined in the HL7 dictionary. If there is any inconsistency observed in the inbound message, the system sends a NACK instead of an ACK message. The system also sends a descriptive message about the inconsistency observed in the message.

You can check with the message sender for correcting the reported errors. If the business needs mandates using the HL7 message with these inconsistencies, then the HL7 dictionary needs to be modified accordingly. The HL7 dictionary defines the structure and semantics of the HL7 message for all supported versions of HL7. The Dictionary files are located under <iWaySMHome>\config\<SelectedConfig>\Hl7\<HL7Version>\Dictionaries folder. These are XML files, but have the extension .xsd.

Messages.xsd defines the supported message types and segment order and repeatability. Segments.xsd defines the structure of all segments and the order and repeatability of Fields. Fields.xsd defines the data type associated with each field. Datatypes.xsd defines the composition of each data type by specifying the order and repeatability of field components and subcomponents.

Changes in the xsd files as described above can be made to fine-tune the validation of HL7 messages as per business requirements.