HL7 (Health Level Seven) is a set of international standards for transfer of clinical and administrative data between software applications in healthcare.
Every HL7 message is comprised of a collection of segments; each segment starts on a new line and is identified by the first three letters on that line and each segment contains fields and subfields.
Within each segment you’ll find fields (separated by pipes – |) and sub fields (separated by carets – ^).
Ex.
MSH|^~\&|iNTERFACEWARE|Lab|Main HIS|... EVN||20110213144532||||20110213145902|... PID|||4525285^^^ADT1||Harrison^Art||... PV1||E||||||5101^Garland^Mary^F^^DR|||||||||||... OBX|||WT^WEIGHT||180|pounds|...
Video: How does HL7 work?
What does an HL7 Message look like?