{
  "resourceType": "NamingSystem",
  "id": "OnMessageEventCodeNS",
  "name": "OnMessageEventCode",
  "status": "draft",
  "kind": "codesystem",
  "date": "2026-09-14",
  "publisher": "WELLSTAR Technologies Corp.",
  "responsible": "eHealth Ontario",
  "description": "The code system an eReferral message names its event under, on `MessageHeader.event[x]`. Published\nby eHealth Ontario; declared here, not minted, so that a reader meeting the system on a message this\nestate sent can recognise it.\n\n**This does not bind `MessageHeader.event[x]`.** The\n[MessageHeader profile](https://fhir.apps.health/fhir/StructureDefinition-nexus-emr-core-messageheader.html) declines to bind that\nelement on purpose, because each eReferral partner brings its own event vocabulary and binding one\nset would make conformant partner traffic non-conformant. A consumer must still handle both the\n`Coding` and the `uri` form of the element.\n\n**This specification publishes no list of the codes in circulation**, and that is deliberate. The\nsystem is eHealth Ontario's, it is published `content: complete`, and its membership is theirs to\nchange on their cadence rather than ours. A list here would be a snapshot of someone else's\nvocabulary that goes stale silently -- as one did: an earlier revision of this text named ten codes\nthis estate sends, and one of them, `notify-add-service-request`, is in no version of eHealth\nOntario's system. The nearest member is `notify-add-service-record`, which is a different event.\n\nRead the membership from the package (`ca.on.erec.r4`), and tolerate a code that is not in the\nversion you hold: a partner may be on a later one.\n\nObtain the code list from eHealth Ontario. It is not reproduced here, because a copy in this\nspecification would be a snapshot revised on someone else's cadence.",
  "uniqueId": [
    {
      "type": "uri",
      "value": "https://ehealthontario.ca/fhir/CodeSystem/message-event-code",
      "preferred": true
    }
  ]
}