Achieving a satisfactory level of integration between different electronic health record (EHR) systems and related products (such as PACS systems) is difficult. In practice, a level of integration we might call syntactic interoperability is achievable through the use of standards such as HL7 v2, CDA, FHIR, or DICOM. But on one level, these are standards for data representation and interchange. It is true that these standards define logical models such as HL7 v2 messages and segments, the RIM in HL7 v3, or resources in FHIR, and these models do help in creating a common vocabulary. But experience has shown that every system interface requires a lot of development effort, and can involve conundrums that are hard to solve (if not downright impossible). Why is…