Provenance of a signature activity against a DiagnosticReport using an electronic signature (no evidence of signature, neither image or digital-signature)

{
  "resourceType" : "Provenance",
  "id" : "example-diagnosticreport-sig",
  "target" : [{
    "reference" : "DiagnosticReport/101"
  }],
  "recorded" : "2011-03-04T08:30:00+11:00",
  "policy" : ["http://example.org/policy/Reviewed"],
  "activity" : {
    "coding" : [{
      "system" : "http://terminology.hl7.org/CodeSystem/iso-21089-lifecycle",
      "code" : "verify"
    }]
  },
  "patient" : {
    "reference" : "Patient/pat2"
  },
  "agent" : [{
    "type" : {
      "coding" : [{
        "system" : "http://terminology.hl7.org/CodeSystem/provenance-participant-type",
        "code" : "verifier",
        "display" : "Verifier"
      }]
    },
    "who" : {
      "reference" : "Organization/1832473e-2fe0-452d-abe9-3cdb9879522f"
    }
  }],
  "signature" : [{
    "type" : [{
      "system" : "http://uri.etsi.org/01903/v1.2.2",
      "code" : "ProofOfapproval",
      "display" : "Proof of approval"
    }],
    "when" : "2011-03-04T08:30:00+11:00",
    "who" : {
      "reference" : "Organization/1832473e-2fe0-452d-abe9-3cdb9879522f"
    }
  }]
}