Appointment Rule app-4 expression is:
Appointment.cancelationReason.exists() implies (Appointment.status='no-show' or Appointment.status='cancelled')

Appointment.status is required-bound to codes, and the code is "noshow" instead of "no-show".

This prevents the use of a Appointment.cancellationReason with the value Appointment.status="noshow", since the rule is checking against the wrong code.

This is impacting our FHIR R4 implementation, as we are unable to process cancellations due to noshows.

Can this be fixed in a FHIR R4 errata (4.0.2?), or will this need to be fixed only in an errata to R4B or R5?

See https://chat.fhir.org/#narrow/stream/179166-implementers/topic/Appointment.20Invariant.20app-4.20uses.20wrong.20status.20code.20'no-show' for confirmation/response from Lloyd McKenzie