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-ReportCodeSnCT-1",
  "url": "https://fhir.hl7.org.uk/STU3/ValueSet/CareConnect-ReportCodeSnCT-1",
  "version": "1.1.0",
  "name": "Care Connect Report Code SnCT",
  "status": "draft",
  "date": "2019-06-14T00:00:00+00:00",
  "publisher": "HL7 UK",
  "description": "A code from the SNOMED Clinical Terminology UK coding system that describes a diagnotic report",
  "copyright": "This value set includes content from SNOMED CT, which is copyright © 2002+ International Health Terminology Standards Development Organisation (IHTSDO), and distributed by agreement between IHTSDO and HL7. Implementer use of SNOMED CT is not covered by this agreement.",
  "compose": {
    "include": [
      {
        "system": "http://snomed.info/sct",
        "filter": [
          {
            "property": "constraint",
            "op": "=",
            "value": "(<<371525003 | Clinical procedure report (record artifact))"
          }
        ]
      }
    ]
  }
}