This code system http://hl7.org/fhir/action-participant-type defines the following codes:

CodeDisplayDefinition
careteam CareTeamThe participant is a care team caring for the patient under evaluation.
device DeviceThe participant is a system or device used in the care of the patient.
group GroupThe participant is a group of participants involved in the care of the patient.
healthcareservice HealthcareServiceThe participant is an institution that can provide the given healthcare service used in the care of the patient.
location LocationThe participant is a location involved in the care of the patient.
organization OrganizationThe participant is an organization involved in the care of the patient.
patient PatientThe participant is the patient under evaluation.
practitioner PractitionerThe participant is a practitioner involved in the patient's care.
practitionerrole PractitionerRoleThe participant is a particular practitioner role involved in the patient's care.
relatedperson RelatedPersonThe participant is a person related to the patient.
<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="The type of participant for the action."/><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/action-participant-type"/><content value="complete"/><concept><code value="careteam"/><display value="CareTeam"/><definition value="The participant is a care team caring for the patient under evaluation."/></concept><concept><code value="device"/><display value="Device"/><definition value="The participant is a system or device used in the care of the patient."/></concept><concept><code value="group"/><display value="Group"/><definition value="The participant is a group of participants involved in the care of the patient."/></concept><concept><code value="healthcareservice"/><display value="HealthcareService"/><definition value="The participant is an institution that can provide the given healthcare service used in the care of the patient."/></concept><concept><code value="location"/><display value="Location"/><definition value="The participant is a location involved in the care of the patient."/></concept><concept><code value="organization"/><display value="Organization"/><definition value="The participant is an organization involved in the care of the patient."/></concept><concept><code value="patient"/><display value="Patient"/><definition value="The participant is the patient under evaluation."/></concept><concept><code value="practitioner"/><display value="Practitioner"/><definition value="The participant is a practitioner involved in the patient's care."/></concept><concept><code value="practitionerrole"/><display value="PractitionerRole"/><definition value="The participant is a particular practitioner role involved in the patient's care."/></concept><concept><code value="relatedperson"/><display value="RelatedPerson"/><definition value="The participant is a person related to the patient."/></concept></CodeSystem>