During v2-to-FHIR mapping review of the AIS segment there was some confusion about what to map it to on Appointment.  Both the .serviceType and .basedOn(ServiceRequest) would be appropriate.  If the AIS only includes AIS-3 Universal Service Identifier, then .serviceType would be sufficient and appropriate.  But if other fields were valued as well, then .basedOn(ServiceRequest would have to be used consider that starts to represent the services being requested for a certain time window during the appointment.

The suggestion is to rename Appointment.serviceType to Appointment.service using the CodeableReference data type where the reference is to ServiceRequest and remove .basedOn.  If not pursued, at least the name of .serviceType is suggeted to be changed to .service while adding clarifications that the value set would be similar/same as the value set used for ServiceRequest.code as in essence that is the same concept.