This is the Continuous Integration Build of FHIR (will be incorrect/inconsistent at times).
See the Directory of published versions 
8.22.8 Resource Communication - Mappings
Mappings for the communication resource (see Mappings to Other Standards for further information & status).
Communication | workflow.encounter |
identifier | FiveWs.identifier |
status | FiveWs.status |
category | FiveWs.class |
priority | FiveWs.grade |
subject | FiveWs.subject[x] |
topic | FiveWs.context |
about | FiveWs.context |
encounter | FiveWs.context |
sent | FiveWs.done[x] |
received | FiveWs.done[x] |
recipient | FiveWs.actor |
sender | FiveWs.actor |
reason | FiveWs.why[x] |
Communication | Event |
identifier | Event.identifier |
instantiatesCanonical | Event.instantiatesCanonical |
instantiatesUri | Event.instantiatesUri |
basedOn | Event.basedOn |
partOf | Event.partOf |
status | Event.status |
statusReason | Event.statusReason |
subject | Event.subject |
encounter | Event.encounter |
sent | Event.occurrence[x] {Invariant: maps to period.start} |
received | Event.occurrence[x] {Invariant: maps to period.end} |
recipient | Event.performer.actor |
sender | Event.performer.actor |
reason | Event.reason |
note | Event.note |
Communication | |
instantiatesCanonical | .outboundRelationship[typeCode=DEFN].target |
instantiatesUri | .outboundRelationship[typeCode=DEFN].target |
reason | .reasonCode |