This code system http://terminology.hl7.org/CodeSystem/endpoint-connection-type defines the following codes:

CodeDisplayDefinition
ihe-xcpd IHE XCPDIHE Cross Community Patient Discovery Profile (XCPD) - http://wiki.ihe.net/index.php/Cross-Community_Patient_Discovery
ihe-xca IHE XCAIHE Cross Community Access Profile (XCA) - http://wiki.ihe.net/index.php/Cross-Community_Access
ihe-xdr IHE XDRIHE Cross-Enterprise Document Reliable Exchange (XDR) - http://wiki.ihe.net/index.php/Cross-enterprise_Document_Reliable_Interchange
ihe-xds IHE XDSIHE Cross-Enterprise Document Sharing (XDS) - http://wiki.ihe.net/index.php/Cross-Enterprise_Document_Sharing
ihe-iid IHE IIDIHE Invoke Image Display (IID) - http://wiki.ihe.net/index.php/Invoke_Image_Display
dicom-wado-rs DICOM WADO-RSDICOMweb RESTful Image Retrieve - http://dicom.nema.org/medical/dicom/current/output/chtml/part18/sect_6.5.html
dicom-qido-rs DICOM QIDO-RSDICOMweb RESTful Image query - http://dicom.nema.org/medical/dicom/current/output/chtml/part18/sect_6.7.html
dicom-stow-rs DICOM STOW-RSDICOMweb RESTful image sending and storage - http://dicom.nema.org/medical/dicom/current/output/chtml/part18/sect_6.6.html
dicom-wado-uri DICOM WADO-URIDICOMweb Image Retrieve - http://dicom.nema.org/dicom/2013/output/chtml/part18/sect_6.3.html
hl7-fhir-rest HL7 FHIRInteract with the server interface using FHIR's RESTful interface. For details on its version/capabilities you should connect the value in Endpoint.address and retrieve the FHIR CapabilityStatement.
hl7-fhir-msg HL7 FHIR MessagingUse the servers FHIR Messaging interface. Details can be found on the messaging.html page in the FHIR Specification. The FHIR server's base address is specified in the Endpoint.address property.
hl7v2-mllp HL7 v2 MLLPHL7v2 messages over an LLP TCP connection
secure-email Secure emailEmail delivery using a digital certificate to encrypt the content using the public key, receiver must have the private key to decrypt the content
direct-project Direct ProjectDirect Project information - http://wiki.directproject.org/
 <status value="draft"/> <experimental value="false"/> <date value="2022-02-23T19:42:18-07:00"/> <publisher value="HL7 Patient Administration"/> <contact> <telecom> <system value="url"/> <value value="http://hl7.org/fhir"/> </telecom> </contact> <description value="This is an example value set defined by the FHIR project, that could be used to represent possible connection type profile values."/> <copyright value="Some content from IHE® Copyright © 2015 IHE International, Inc. This content is from the IHE Technical Frameworks and Supplements, available for free download and use at http://www.ihe.net/Technical_Frameworks/"/> <caseSensitive value="true"/> <valueSet value="http://terminology.hl7.org/ValueSet/endpoint-connection-type"/> <content value="complete"/> <concept> <code value="ihe-xcpd"/> <display value="IHE XCPD"/> <definition value="IHE Cross Community Patient Discovery Profile (XCPD) - http://wiki.ihe.net/index.php/Cross-Community_Patient_Discovery"/> </concept> <concept> <code value="ihe-xca"/> <display value="IHE XCA"/> <definition value="IHE Cross Community Access Profile (XCA) - http://wiki.ihe.net/index.php/Cross-Community_Access"/> </concept> <concept> <code value="ihe-xdr"/> <display value="IHE XDR"/> <definition value="IHE Cross-Enterprise Document Reliable Exchange (XDR) - http://wiki.ihe.net/index.php/Cross-enterprise_Document_Reliable_Interchange"/> </concept> <concept> <code value="ihe-xds"/> <display value="IHE XDS"/> <definition value="IHE Cross-Enterprise Document Sharing (XDS) - http://wiki.ihe.net/index.php/Cross-Enterprise_Document_Sharing"/> </concept> <concept> <code value="ihe-iid"/> <display value="IHE IID"/> <definition value="IHE Invoke Image Display (IID) - http://wiki.ihe.net/index.php/Invoke_Image_Display"/> </concept> <concept> <code value="dicom-wado-rs"/> <display value="DICOM WADO-RS"/> <definition value="DICOMweb RESTful Image Retrieve - http://dicom.nema.org/medical/dicom/current/output/chtml/part18/sect_6.5.html"/> </concept> <concept> <code value="dicom-qido-rs"/> <display value="DICOM QIDO-RS"/> <definition value="DICOMweb RESTful Image query - http://dicom.nema.org/medical/dicom/current/output/chtml/part18/sect_6.7.html"/> </concept> <concept> <code value="dicom-stow-rs"/> <display value="DICOM STOW-RS"/> <definition value="DICOMweb RESTful image sending and storage - http://dicom.nema.org/medical/dicom/current/output/chtml/part18/sect_6.6.html"/> </concept> <concept> <code value="dicom-wado-uri"/> <display value="DICOM WADO-URI"/> <definition value="DICOMweb Image Retrieve - http://dicom.nema.org/dicom/2013/output/chtml/part18/sect_6.3.html"/> </concept> <concept> <code value="hl7-fhir-rest"/> <display value="HL7 FHIR"/> <definition value="Interact with the server interface using FHIR's RESTful interface. For details on its version/capabilities you should connect the value in Endpoint.address and retrieve the FHIR CapabilityStatement."/> </concept> <concept> <code value="hl7-fhir-msg"/> <display value="HL7 FHIR Messaging"/> <definition value="Use the servers FHIR Messaging interface. Details can be found on the messaging.html page in the FHIR Specification. The FHIR server's base address is specified in the Endpoint.address property."/> </concept> <concept> <code value="hl7v2-mllp"/> <display value="HL7 v2 MLLP"/> <definition value="HL7v2 messages over an LLP TCP connection"/> </concept> <concept> <code value="secure-email"/> <display value="Secure email"/> <definition value="Email delivery using a digital certificate to encrypt the content using the public key, receiver must have the private key to decrypt the content"/> </concept> <concept> <code value="direct-project"/> <display value="Direct Project"/> <definition value="Direct Project information - http://wiki.directproject.org/"/> </concept> </CodeSystem>