Beginning of clinical encounter (Parameters)

{
  "resourceType" : "SubscriptionTopic",
  "id" : "admission-parameters",
  "extension" : [{
    "url" : "http://hl7.org/fhir/StructureDefinition/structuredefinition-wg",
    "valueCode" : "fhir"
  }],
  "url" : "http://example.org/FHIR/SubscriptionTopic/admission-parameters",
  "identifier" : [{
    "system" : "urn:ietf:rfc:3986",
    "value" : "urn:uuid:6651a462-e65e-4ef1-9bab-b3ae997e5be9"
  }],
  "title" : "admission-parameters",
  "status" : "active",
  "publisher" : "HL7 International / FHIR Infrastructure",
  "contact" : [{
    "telecom" : [{
      "system" : "url",
      "value" : "http://www.hl7.org/Special/committees/fiwg"
    }]
  }],
  "description" : "Example admission topic using a Parameters representation",
  "trigger" : [{
    "description" : "Patient admission or visit begins.",
    "resource" : "Parameters",
    "supportedInteraction" : ["create",
    "update"],
    "event" : {
      "coding" : [{
        "system" : "http://terminology.hl7.org/CodeSystem/v2-0003",
        "code" : "A01",
        "display" : "ADT/ACK - Admit/visit notification"
      }]
    },
    "canFilterBy" : [{
      "description" : "Matching based on the Patient MRN, expected to be in a `part` named `mrn` and contain a `string` value, matched using `token` search rules.",
      "resource" : "Parameters",
      "filterParameter" : "MRN"
    }],
    "notificationShape" : [{
      "resource" : "Parameters"
    }]
  }]
}