<?xml version="1.0" encoding="UTF-8"?><CodeSystem xmlns="http://hl7.org/fhir"><id value="messageheader-response-request"/><meta><lastUpdated value="2026-03-31T18:55:04.283+00:00"/></meta><text><status value="generated"/><div xmlns="http://www.w3.org/1999/xhtml"><p class="res-header-id"><b>Generated Narrative: CodeSystem messageheader-response-request</b></p><a name="messageheader-response-request"> </a><a name="hcmessageheader-response-request"> </a><p>This case-sensitive code system <code>http://hl7.org/fhir/messageheader-response-request</code> defines the following codes:</p><table class="codes"><tr><td style="white-space:nowrap"><b>Code</b></td><td><b>Display</b></td><td><b>Definition</b></td></tr><tr><td style="white-space:nowrap">always<a name="messageheader-response-request-always"> </a></td><td>Always</td><td>initiator expects a response for this message.</td></tr><tr><td style="white-space:nowrap">on-error<a name="messageheader-response-request-on-error"> </a></td><td>Error/reject conditions only</td><td>initiator expects a response only if in error.</td></tr><tr><td style="white-space:nowrap">never<a name="messageheader-response-request-never"> </a></td><td>Never</td><td>initiator does not expect a response.</td></tr><tr><td style="white-space:nowrap">on-success<a name="messageheader-response-request-on-success"> </a></td><td>Successful completion only</td><td>initiator expects a response only if successful.</td></tr></table></div></text><extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-wg"><valueCode value="inm"/></extension><extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status"><valueCode value="normative"/></extension><extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm"><valueInteger value="1"/></extension><url value="http://hl7.org/fhir/messageheader-response-request"/><identifier><system value="urn:ietf:rfc:3986"/><value value="urn:oid:2.16.840.1.113883.4.642.4.925"/></identifier><identifier><use value="old"/><system value="urn:ietf:rfc:3986"/><value value="urn:oid:2.16.840.1.113883.4.642.1.844"/></identifier><version value="6.0.0-ballot4"/><name value="MessageheaderResponseRequest"/><title value="messageheader-response-request"/><status value="active"/><experimental value="false"/><date value="2021-01-05T10:01:24+11:00"/><publisher value="HL7 (FHIR Project)"/><contact><telecom><system value="url"/><value value="http://hl7.org/fhir"/></telecom><telecom><system value="email"/><value value="fhir@lists.hl7.org"/></telecom></contact><description value="HL7-defined table of codes which identify conditions under which acknowledgments are required to be returned in response to a message."/><jurisdiction><coding><system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/><code value="001"/><display value="World"/></coding></jurisdiction><caseSensitive value="true"/><valueSet value="http://hl7.org/fhir/ValueSet/messageheader-response-request"/><content value="complete"/><concept><code value="always"/><display value="Always"/><definition value="initiator expects a response for this message."/></concept><concept><code value="on-error"/><display value="Error/reject conditions only"/><definition value="initiator expects a response only if in error."/></concept><concept><code value="never"/><display value="Never"/><definition value="initiator does not expect a response."/></concept><concept><code value="on-success"/><display value="Successful completion only"/><definition value="initiator expects a response only if successful."/></concept></CodeSystem>