{
  "schema": "vedokrok.public-item.v1",
  "release_id": "MHC-RPUB-20260920-75ad787a",
  "url": "/knowledge/match-the-identifier-together-with-its-issuing-namespace",
  "id": "MHC-D-RESEARCH-0988",
  "version": "0.1.0",
  "title": "Match the identifier together with its issuing namespace",
  "summary": "Record 123 in one system has not introduced itself to record 123 in another.",
  "kind": "template",
  "body": "Treat an identifier as a value inside an issuing namespace. Use an authoritative crosswalk when matching across namespaces, and preserve both original identities. A shared name or number is a candidate match, not sufficient proof of equivalence.",
  "limits": [
    "Identifiers may be merged or reassigned. Record validity periods and ambiguous matches instead of forcing a one-to-one mapping that the domain does not support."
  ],
  "topics": [
    "work-02-data-reconciliation"
  ],
  "intents": [],
  "source_ids": [
    "RS-F863D183EF6C607D"
  ],
  "evidence": [
    {
      "claim": "FHIR Identifier separates the namespace in system from the identifier string in value, avoiding reliance on the value alone for identity.",
      "source_id": "RS-F863D183EF6C607D",
      "role": "supports",
      "note": "A crosswalk still needs an authoritative mapping and rules for reassignment, merges and validity periods.",
      "locator": "Identifier.system and Identifier.value"
    }
  ],
  "use_when": [
    "Two systems use the same-looking number for potentially different entities."
  ],
  "avoid_when": [
    "Identifiers may be merged or reassigned. Record validity periods and ambiguous matches instead of forcing a one-to-one mapping that the domain does not support."
  ],
  "example": "Customer 123 in a legacy system maps to partner 900123 in the new system. An unrelated target customer numbered 123 must not capture the relationship.",
  "check": "Every accepted cross-system match has a namespace-aware rule or traceable mapping decision.",
  "template": "Source namespace: [source system]. Source value: [source id]. Target namespace: [target system]. Target value: [target id]. Mapping authority and validity: [basis].",
  "sources": [
    {
      "id": "RS-F863D183EF6C607D",
      "title": "FHIR datatypes: Identifier",
      "url": "https://hl7.org/fhir/datatypes.html#Identifier"
    }
  ],
  "relations": [
    {
      "from": "MHC-D-RESEARCH-0988",
      "to": "MHC-D-RESEARCH-0980",
      "type": "useful_with",
      "url": "/knowledge/name-what-one-row-means-before-joining-two-tables"
    }
  ],
  "collections": [
    {
      "id": "RC-1B134BE48D7DF2A0",
      "title": "Keep the meaning intact when data moves",
      "url": "/collections/keep-the-meaning-intact-when-data-moves"
    }
  ]
}