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": "GPConnect-SecondaryListValues-1",
  "url": "https://fhir.hl7.org.uk/STU3/CodeSystem/GPConnect-SecondaryListValues-1",
  "version": "1.0.0",
  "name": "GPConnect Secondary List Values",
  "status": "active",
  "date": "2020-09-25T17:21:47+00:00",
  "publisher": "HL7 UK",
  "description": "A CodeSystem to identify the secondary list values.",
  "copyright": "Copyright © 2020 HL7 UK",
  "caseSensitive": true,
  "content": "complete",
  "concept": [
    {
      "code": "consultations-allergies-contained-in-consultations",
      "display": "Consultations - allergies contained in consultations"
    },
    {
      "code": "consultations-allergies-that-have-been-ended-contained-in-consultations",
      "display": "Consultations - allergies that have been ended contained in consultations"
    },
    {
      "code": "consultations-diary-entries-contained-in-consultations",
      "display": "Consultations - diary entries contained in consultations"
    },
    {
      "code": "consultations-documents-contained-in-consultations",
      "display": "Consultations - documents contained in consultations"
    },
    {
      "code": "consultations-immunisations-contained-in-consultations",
      "display": "Consultations - immunisations contained in consultations"
    },
    {
      "code": "consultations-investigations-contained-in-consultations",
      "display": "Consultations - investigations contained in consultations"
    },
    {
      "code": "consultations-medications-contained-in-consultations",
      "display": "Consultations - medications contained in consultations"
    },
    {
      "code": "consultations-outbound-referrals-in-consultations",
      "display": "Consultations - outbound referrals in consultations"
    },
    {
      "code": "consultations-problems-contained-in-consultations",
      "display": "Consultations - problems contained in consultations"
    },
    {
      "code": "consultations-uncategorised-data-contained-in-consultations",
      "display": "Consultations - uncategorised data contained in consultations"
    },
    {
      "code": "problems-allergies-related-to-problems",
      "display": "Problems - allergies related to problems"
    },
    {
      "code": "problems-allergies-that-have-been-ended-related-to-problems",
      "display": "Problems - allergies that have been ended related to problems"
    },
    {
      "code": "problems-consultations-related-to-problems",
      "display": "Problems - consultations related to problems"
    },
    {
      "code": "problems-diary-entries-related-to-problems",
      "display": "Problems - diary entries related to problems"
    },
    {
      "code": "problems-documents-related-to-problems",
      "display": "Problems - documents related to problems"
    },
    {
      "code": "problems-immunisations-related-to-problems",
      "display": "Problems - immunisations related to problems"
    },
    {
      "code": "problems-investigations-related-to-problems",
      "display": "Problems - investigations related to problems"
    },
    {
      "code": "problems-medications-related-to-problems",
      "display": "Problems - medications related to problems"
    },
    {
      "code": "problems-outbound-referrals-related-to-problems",
      "display": "Problems - outbound referrals related to problems"
    },
    {
      "code": "problems-linked-problems-not-relating-to-the-primary-query",
      "display": "Problems - linked problems not relating to the primary query"
    },
    {
      "code": "problems-uncategorised-data-related-to-problems",
      "display": "Problems - uncategorised data related to problems"
    }
  ]
}