Hl7 v2 has both Appointment Type and Appointmnet Reason, as effectively FHIR Appointment has (appointmentType and reasonCode).  Unfortunately, Appointment.appointmentType suggests to use HL7 v2 table 0276 which represents reasons, while Appointment.reasonCode suggests to use encounter reason codes.  Suggest that Appointment.appointmentType switches to HL7 v2 table 0277 to be consistent with HL7 v2 and then we can map the Hl7 v2 reaons codes to the enocunter reason codes, which would be consistent.  One could use the current HL7 v2 0276 values as they sound more like type and create a FHIR code system/value set for that.  But not reference HL7 0276.