f:ContactPoint system: minimum cardinality of 'system' is 1 value: minimum cardinality of 'value' is 1 ContactPoint A system is required if a value is provided. (inherited) All FHIR elements must have a @value or children (inherited) ContactPoint.extension All FHIR elements must have a @value or children Must have either extensions or value[x], not both ContactPoint.system All FHIR elements must have a @value or children (inherited) ContactPoint.value All FHIR elements must have a @value or children (inherited) ContactPoint.use All FHIR elements must have a @value or children (inherited) ContactPoint.rank All FHIR elements must have a @value or children (inherited) f:ContactPoint/f:period id: maximum cardinality of 'id' is 1 start: maximum cardinality of 'start' is 1 end: maximum cardinality of 'end' is 1 ContactPoint.period All FHIR elements must have a @value or children (inherited) ContactPoint.period.extension All FHIR elements must have a @value or children Must have either extensions or value[x], not both ContactPoint.period.start All FHIR elements must have a @value or children (inherited) ContactPoint.period.end All FHIR elements must have a @value or children (inherited)