HL7 V2 messaging is widely used in Australia, including the transmission of Pathology results from laboratories to providers. This section provides a broad overview of the format and function of pathology messages before detailing specific elements in detail. Electronic ordering is less well developed currently but is used in some arenas and provides significant potential advantages for the requester and filler of laboratory tests.
HL7 V2 was developed before the introduction of xml or json and the format is text based and unique the HL7 v2. It was originally designed to pass 7 bit channels and optimizes file size and in Australia is restricted to the ASCII character set as described in the appendix on parsing HL7 v2. Implementers should read and understand this appendix. The file format contains no field names and requires pre-existing knowledge of its structure to process. It is highly storage and bandwidth efficient however.