Optional_Optional_accepted | declined | tentative | needs-action
OptionalactorPerson, Location/HealthcareService or Device
OptionalextensionAdditional content defined by implementations
OptionalidUnique id for inter-element referencing
OptionalmodifierExtensions that cannot be ignored even if unrecognized
OptionalperiodParticipation period of the actor
Optionalrequiredrequired | optional | information-only
accepted | declined | tentative | needs-action
OptionaltypeRole of participant in the appointment
required | optional | information-only