This is the Continuous Integration Build of FHIR (will be incorrect/inconsistent at times).
See the Directory of published versions 
| OperationOutcome |
Grouping is handled through multiple repetitions from whatever context references the outcomes (no specific grouper required) |
| issue |
AcknowledgementDetail or Observation[classCode="ALRT" and moodCode="EVN"] |
| severity |
./typeCode[parent::AcknowledgmentDetail] or unique(./inboundRelationship[parent::Observation and typeCode='SUBJ' and isNormalActRelationship()]/source[classCode="OBS" and moodCode="EVN" and implies(code, ActCode#SEV and isNormalAct())/value[xsi:type="CD"] |
| code |
./code |
| details |
./code |
| diagnostics |
./text[parent::AcknowledgmentDetail] |
| location |
./location[parent::AcknowledgmentDetail] |
| expression |
./location[parent::AcknowledgmentDetail] |