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": "CodeSystem",
  "id": "CareConnect-ListWarningCode-1",
  "url": "https://fhir.hl7.org.uk/STU3/CodeSystem/CareConnect-ListWarningCode-1",
  "version": "1.2.0",
  "name": "Care Connect List Warning Code",
  "status": "draft",
  "date": "2018-11-01T00:00:00+00:00",
  "publisher": "HL7 UK",
  "description": "A CodeSystem to identify the reason a list may be incomplete.",
  "copyright": "Copyright © 2016 HL7 UK",
  "caseSensitive": true,
  "content": "complete",
  "concept": [
    {
      "code": "confidential-items",
      "display": "Confidential Items",
      "definition": "Items excluded due to confidentiality and/or patient preferences."
    },
    {
      "code": "data-in-transit",
      "display": "Data in Transit",
      "definition": "Patient record transfer from previous GP practice not yet complete; any information recorded before dd-mmm-yyyy has been excluded."
    },
    {
      "code": "data-awaiting-filing",
      "display": "Data Awaiting Filing",
      "definition": "Patient data may be incomplete as there is data supplied by a third party awaiting review before becoming available."
    }
  ]
}