This case-sensitive code system http://fhir.kisimdocs.ch/ig/KisimScheduling/CodeSystem/service-request-category defines the following codes:

CodeDisplayDefinition
AppointmentBooking Booking of an AppointmentServiceRequest for the booking of an appointment.
PatientTask Request of a patient taskTask from a Patient to a Service Provider, HealthCare professional.
PatientPortal Communication with a patient portalUsed to send a message from the patient portal.
DocumentReferral Referral of a documentUsed to submit a document to a system.
Sighting Sighting of the referral.Used to sight the referral.
 <status value="active"/> <experimental value="true"/> <date value="2023-12-19T13:36:49+01:00"/> <publisher value="Cistec AG"/> <contact> <name value="Cistec AG"/> <telecom> <system value="url"/> <value value="https://www.cistec.com"/> </telecom> <telecom> <system value="email"/> <value value="robert.birri@cistec.com"/> </telecom> </contact> <description value="ServiceRequest category codes"/> <jurisdiction> <coding> <system value="urn:iso:std:iso:3166"/> <code value="CH"/> </coding> </jurisdiction> <caseSensitive value="true"/> <content value="complete"/> <count value="5"/> <concept> <code value="AppointmentBooking"/> <display value="Booking of an Appointment"/> <definition value="ServiceRequest for the booking of an appointment."/> </concept> <concept> <code value="PatientTask"/> <display value="Request of a patient task"/> <definition value="Task from a Patient to a Service Provider, HealthCare professional."/> </concept> <concept> <code value="PatientPortal"/> <display value="Communication with a patient portal"/> <definition value="Used to send a message from the patient portal."/> </concept> <concept> <code value="DocumentReferral"/> <display value="Referral of a document"/> <definition value="Used to submit a document to a system."/> </concept> <concept> <code value="Sighting"/> <display value="Sighting of the referral."/> <definition value="Used to sight the referral."/> </concept> </CodeSystem>