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.
<ConceptMap xmlns="http://hl7.org/fhir">
   <id value="CareConnect-ConditionEpisodicity-1"></id>
   <text>
      <status value="generated"></status>
   </text>
   <url value="https://fhir.hl7.org.uk/STU3/ConceptMap/CareConnect-ConditionEpisodicity-1"></url>
   <version value="1.1.0"></version>
   <name value="Concept Map - Condition Episodicity"></name>
   <status value="draft"></status>
   <date value="2018-11-14T00:00:00+00:00"></date>
   <publisher value="HL7 UK"></publisher>
   <description value="A Concept Map from ValueSet Condition Episodicity Severity to equivalent Snomed CT codes"></description>
   <copyright value="Copyright © 2016 HL7 UK"></copyright>
   <sourceReference>
      <reference value="https://fhir.hl7.org.uk/STU3/ValueSet/CareConnect-ConditionEpisodicity-1"></reference>
   </sourceReference>
   <targetReference>
      <reference value="https://fhir.hl7.org.uk/STU3/ValueSet/CareConnect-ConditionEpisodeSnCT-1"></reference>
   </targetReference>
   <group>
      <source value="https://fhir.hl7.org.uk/STU3/CodeSystem/CareConnect-ConditionEpisodicity-1"></source>
      <target value="http://snomed.info/sct"></target>
      <element>
         <code value="first"></code>
         <display value="First"></display>
         <target>
            <code value="255217005"></code>
            <display value="First episode"></display>
            <equivalence value="equivalent"></equivalence>
         </target>
      </element>
      <element>
         <code value="new"></code>
         <display value="New"></display>
         <target>
            <code value="288527008"></code>
            <display value="New episode"></display>
            <equivalence value="equivalent"></equivalence>
         </target>
      </element>
      <element>
         <code value="review"></code>
         <display value="Review"></display>
         <target>
            <code value="303350001"></code>
            <display value="Ongoing episode"></display>
            <equivalence value="equivalent"></equivalence>
         </target>
      </element>
      <element>
         <code value="end"></code>
         <display value="End"></display>
         <target>
            <code value="272131007"></code>
            <display value="Old episode"></display>
            <equivalence value="equivalent"></equivalence>
         </target>
      </element>
   </group>
</ConceptMap>