HL7

Legacy healthcare messaging standard (v2.x) for clinical + administrative data. ORM (orders), ORU (results), ADT (admit/discharge/transfer) are core.

Why it matters to buyers: Underpins most hospital interfaces today. FHIR is the successor but v2 is entrenched.

Why it matters to engineers: Parsing is character-delimited, not XML/JSON. Hospital interface engines (Mirth, Cloverleaf) translate between HL7 dialects.