This is a HL7 FHIR server, and as you appear to be accessing this page from a web browser you are seeing a HTML version of the requested resource(s). You can also access this URL from a FHIR client as a ReSTful API call. For more details please see the HL7 FHIR specification.
{
  "resourceType": "ValueSet",
  "id": "CareConnect-InterpretationCode-1",
  "url": "https://fhir.hl7.org.uk/STU3/ValueSet/CareConnect-InterpretationCode-1",
  "version": "1.0.0",
  "name": "Care Connect Extended Interpretation Code",
  "status": "draft",
  "date": "2019-03-12T00:00:00+00:00",
  "publisher": "HL7 UK",
  "description": "This value set defines the set of extended codes that can be used to indicate the meaning/use of a reference range.",
  "copyright": "HL7",
  "extensible": true,
  "compose": {
    "include": [
      {
        "system": "https://fhir.hl7.org.uk/STU3/CodeSystem/CareConnect-ExtendedInterpretationCode-1",
        "concept": [
          {
            "code": "OR",
            "display": "Outside Reference Range"
          },
          {
            "code": "PA",
            "display": "Potentially Abnormal"
          }
        ]
      }
    ]
  }
}