f:Extension value[x]: minimum cardinality of 'value[x]' is 1 Extension.extension All FHIR elements must have a @value or children Must have either extensions or value[x], not both f:Extension/f:value[x] 1 reference: minimum cardinality of 'reference' is 1 type: maximum cardinality of 'type' is 0 identifier: maximum cardinality of 'identifier' is 0 display: maximum cardinality of 'display' is 0 Extension.value[x] 1 All FHIR elements must have a @value or children (inherited) Extension.value[x].extension 1 All FHIR elements must have a @value or children Must have either extensions or value[x], not both Extension.value[x].reference 1 All FHIR elements must have a @value or children (inherited) Extension.value[x].type 1 All FHIR elements must have a @value or children (inherited) Extension.value[x].identifier 1 All FHIR elements must have a @value or children (inherited) Extension.value[x].display 1 All FHIR elements must have a @value or children (inherited)