After reading wiki and official document, they say:
HL7 v3 messages are based on an XML encoding syntax.
Okay, it seems clear it should be XML.
But does "based on" mean "can only be", is it possible to use another format? (e.g. the old pipe delimited format like HL7v2 )
In short, no.
HL7 V3 begins with what is termed a Reference Information Model. This object model is significantly expanded and all encompassing of each previous version of HL7 V2 messages.
The significant difference between all previous version of HL7 and the latest V3, is that previously there was a large number of diverse event types (messages) and varying vocabulary and semantics. V3 provides enormous message schemas (XML of course) used to achieve many of the old event types, and each element (field) has extensive semantic definition including unique identifiers (OIDs) for all code values and their respective coding systems.
I hope this helps.
